You need to take into account more than price.

Warranty and installation plays a big part. Depending on what you buy, return shipping cost, availability of quick replacement etc. can all hinder and slow down and cause big problems in your building schedule.

If you buy on line and have something delivered the subs will not always take on the hassle of warranty repairs or getting the company to provide a replacement. That becomes your job.

The builder doesn't have an issue with it. Dealing with warranty returns ourselves is no big deal. We do it when necessary. I would not expect the subs or builder to handle warranty matters for something we supplied.

I have been buying on-line since they started selling over the Internet. We almost never have warranty issues.

We built out in the "country" and our builder didn't have a "recommended" source for appliances so we ordered from Sears. We ordered in the fall when we were able to get a great sale and Sears kept the appliances until we were ready for them(in the Spring). It worked out perfectly for us!
As for cabinets the builder had better sources than what we were comfortable choosing on our own. Lighting fixtures we purchased online and box stores. We always had the choice and most of the time we went with the builders sources.
HTH

My builder when we gave him a selection often just ordered it on-line. As a for instance - the plumber gets good prices on Moen and Delta so that can't be beat. For Grohe, we ordered online (or rather - the builder did for us). When I told the electrician that I wanted a better fan with heater for the master, he said get it here. I ordered in online and they installed it (along with the HVAC to hook it up).

As for lighting - the local lighting store is exactly the same price I can find online which makes me think there are pricing agreements with the manufacturers. The rate we get is 50% off retail.

Sales tax is a big consideration and I'll say no more since that creates a whole host of opinions and controversy.

I was the Ebay Queen when I was building my house and found great deals on lighting and many other things. My major lighting purchases were about 70% off retail as I was lucky to get an interior decorator who purchased more than he needed. One light had been a store sample and was just missing a globe. I ordered the required globe at a local lighting store. I also got my undermount stainless steel sink for about $150 which cost $500+ other places. Decorative wood corbels for the fireplace and cabinets were other great finds on ebay. Much cheaper than the builder or home depot could offer. All of these were purchased on ebay separate from my builder's allowance which made it stretch much further and I was able to get more of what I wanted. It pays to do your homework. I have been in my house 3 years now and have had no issues with anything I purchased from ebay...you have to pay attention to the seller's feedback ratings. Bottomline anything you imagine you might need is available there.

Most of the things a builder normally uses in a house are things he can get a discount on, and therefore make a bigger profit on. They are usually not the highest quality items. You can shop around (Ebay is a great place to start) and usually get higher quality items for less money.

we wern't impressed by our builder "discounts". I would definately shop around. In some cases we went with the builder supplier (e.g. lighting, cabinets) but in other cases we found a better local supplier and now the builder has switched over to them (e.g.granite). In some cases we purchased items on line and gave them to the builder (e.g. sinks). In the case of the lighting, we did not get the absolute best price on the fixtures (although the prices were good and dicounted off suggested retail) BUT we did get a "free" design and that was well worth the small premium on the fixtures. We could have saved a few dollars by puchasing the same lights on-line but we did have some broken fixtures on delivery (replaced quickly) and the lighting in our house is fantastic.

There is something to be said for having a local supplier who can quickly get you parts or replace an item if there are problems. But you have to weigh that against what you are getting locally and any savings you can get on line.

For example, we purchased our faucets locally using the builder's plumbing supplier but we bought the stainless steel sinks on line. The markup on SS was unbelievable (2 grand for a Kohler kitchen sink with the "discount" - are they nuts!). I think we paid 1 grand for 4 SS sinks - 16 gauage - they are awesome and we got that tip from GW. So Scrutinize every line item and do not assume that every item on the list is at the best discount you can get. Toilets were another one - we bought Toto's on-line and got a very good deal.

The appliance purchase was amazing. Builder told us that his guy had the very best prices. BS - we saved over 4 grand by buying appliances from a local store who has been around for decades and their price included installation!. Plus we got 0% financing on the stuff which we just finished paying off - nice to have that off the mortgage. I don't think I would buy appliances on-line - research that approach and definately don't be affraid to check local stores and tell them the best prices you can get on line - see if they will at least match it or throw in installation.

Shop til you drop. Its your money that they want to take.

PS - assume that EVERY builder "allowance" is crap - pulled out of the air. Validate every allowance against actual bids from suppliers for items that are at the quality level you expect. Hopefully you can do this before you sign the contract. If we had only budgeted what our builder "allowed", we would have no lights and probably have plywood for countertops.

My only real experience on this was with my plumber. I asked if it was OK for me to do some cross shopping, just buy a faucet etc. I liked if I found it, and that was no problem.

But on the stuff I got from his reccomended wholesaler, I think I ended up paying close to, sometimes over full retail, which in turn is at least 30% over street price.

He gave me 'his discount' from the wholesaler, then charged a 20% markup on that price.

Early in the build we seemed to be going fast and I was worried about holding things up, so I went along with it. Lucky I left some decisions for later: the prep sink I wanted would have run over $400 from the plumber, right around $200 including shipping off ebay.

By the time the first stack of invoices came in so that we could get a look at just how all this worked, it was already to late to change horses.

The builder is not interested in the lowest price, he needs a distributor he can call up and order delivery and know the item will be delivered as ordered and on time.

If installation is delayed, it costs money.

If one faucet is missing, the plumber has to make another trip to install it.

A light fixture requires the electrician to make another trip.

While the builder is not responsible for appliance warranties, he is responsible for installation defects.

Just like I have favored subs who will go the extra mile, do great work, and show up when scheduled, I have favorite vendors for many of the same reasons.

It costs money to make a call, schedule delivery, make sure someone is present to accept delivery (the masonry contractor is not going to sign for appliance and fixture deliveries, even if he is there).

Order your "stuff" enough in advance so that it will be there when needed by the contractor. Have your contract written so that the GC will warranty the installation of the "stuff." The manufacturer should honor the manufacturer's warranty.
Work with your GC on price.