Any cheaper than what?

Cheaper than typical brick & mortar (local building supply stores).

You may get good deals online for finish materials like faucets and knobs, but if you are talking about basic materials like lumber, concrete mix, roofing materials, etc., I doubt that you could find stuff like this at a delivered cost less than local prices.

i've been pricing things out lately and i think ebay is the best option. Raw building materials probably aren't even available to buy online and even if they are, they're not any cheaper. I've seen lots of nice vanities, door handles/hinges, faucets, tubs, etc... on ebay for less than half of brick and mortar shops. Also i really like builddirect.com, i haven't purchased anything from them yet but i plan to buy our wood floors and tile from them.

I don't like paying for something and waiting to see if I got taken.

If you bundle items together, the local suppliers' (plumbing, electrical, etc.) bids can be comparable to or lower than online sites with 100x the service.

To my knowledge general contractors do not do this and they make their living buying materials at the lowest prices. You might want to think about why. See if you can open an account at a local supplier so you can get a discount.

Online (most of these are no particular site):
Faucets
Hardware
Sinks
Prefinished Flooring (still might not beat Lumber Liquidator Price)
Tile (if you're buying pallet qty - I used Builddirect.com)
Solid Wood Doors (I used ETO Doors)

Otherwise, shop around to local supply houses. My experience was that one had the lowest lumber, another had windows less expensive, and a third had the interior doors and trim cheaper. Bid it out to several and then negotiate. You probably won't get more than 1 or 2% off, but every bit helps.

You can definitely get faucets (eFaucets.com) and doorknobs and trim cheaper. Lumber Liquidators is probably your best best for hardwood. I would stay away from eBay just because you're never sure exactly what you're getting. Overstock.com is also good, sometimes. We bought two beautiful vessel sinks there for $70 each. We also bought the marble for our shower and kitchen backsplash online at significant savings. Things like doors, windows, lumber -- it either won't be available online or too expensive to ship.

The faucets -- you can get just about anything at that site. They are definitely cheaper than Lowe's, Home Depot, and your local retailer -- and no sales tax. There are several places online to get doorknobs and cabinet hardware for less as well. We got all our faucets, all our door and cabinet hardware, and 90% of our light fixtures online. We saved some money, but we did it mostly because we couldn't find what we wanted in local stores. It's also a way to tick off your contractor because he's not getting his kick-back from his suppliers that he wants you to use -- so just watch out because he's likely going to be a little miffed.

I have found a site that provides wall and ceiling grilles and registers for the home when I was searching for a replacement register. I did not use the site since I don't believe it is ready for commerce but give it a try.

www.grdglobal.com

www.HomeHardware4Less.com is a great place to get fine residential door hardware and cabinet hardware. They have great prices on Emtek, Nostalgic Warehouse, Schaub Knobs,Top Knobs, and Baldwin hardware.

Here is a link that might be useful: Home Hardware 4 Less

This may not be on topic but GLOCKS RULE!!!! Plastic and iron artwork if you ask me.