Your realtor is full of crap.

The home centers typically carry "in stock" the bottom end of the line because most people shopping there want cheap. It's not a "look alike". A Kohler Wentworth toilet is the same at
HD or anywhere else (except other places stock it in things other than WHITE w/poliched chrome trim).

You can get other things from the line at the special order desk (ask to see the Doodads or "My other warehouse" catalog).

Frankly I don't order that way, because I can usually do better on price at some of the online places such as faucets.com.

I recently read a thread on this from manufacturers of faucets and it seems to be true. At least for SOME faucet makers. Plus, the big box stores don't have much choice--just the fast moving stuff. I found that shopping for faucets online yields more choice and very often the prices are better.

I think it depends on what you mean by "fixtures." Toilets, tubs, etc. are probably the same as anywhere.

Faucets - that's a different story. Many of the brands manufacture special faucets just for HD and Lowes. They may look the same, but the model number will be very slightly different, and often the "innards" are different. Plastic, rather than brass, etc. They may work fine, but they are not the same quality. The prices will be low, and many (most?) people shopping there are unaware of the differences, and probably don't care.

If you see a faucet at HD you like, look on the web and check the model numbers. There may be one number or letter different.

Your realtor may be wiser than most...

Had a plumber tell me toilets at the big box stores are junk, they don't have to pass as stringent a test on the porcline composition, had a contractor tell me that altough Port-Cable is a top brand, don't expect the ones carried at hd & lowes to be the same top quality, and don't expect your john deere tractor to be as good as the ones at a john deere dealer.. okay, I can't spell porcelin.

I agree with Cindy. The faucets' model numbers and materials are different with a lot of the products. During my time as a repair plumber, I had many people hire us to install their previously purchased products. Home Depot, Lowes, Dixieline, etc. More often than not, they would be returning a defective faucet while I waited from them to run back and forth. This happened with Moen, Kohler, Delta, A/S, Grohe, PP, etc.
As for vitreous china products, based on the number of factory defects, I have long believed that HD buys seconds from the factory.

Our Kohler house fixtures (from Lowe's) and all came via a plumbing wholesaler. No way they were substabdard; all P/N's matched the factory numbers on the company website.

Can't speak for other brands, though.

If SKU #'s are the same, the product is the same. If SKU #'s are different, then something is different. Easy as that.