We are in the early stages of building a new house & went shopping for lighting fixtures yesterday. We get an allowance from the builder which we know will be used up very quickly after visiting their standard supplier. We also had a lot of trouble finding fixtures that we really liked (especially ceiling fans).
Later, we went to Home Depot and found quite a few fixtures that we liked, in most cases we liked them better than what we'd seen at the lighting supply store. And the prices were much lower.
We can take the lighting allowance the builder gives us and get it applied as a credit on the final price of the house (or put the money into other upgrades) if we purchase everything on our own and deliver it when they tell us to. If we can do this and save money on the fixtures, that's great. But I worry that the Home Depot (or Lowe's) brands may be of significantly lesser quality, and in 2 years we'll find ourselves having to replace a number of them.
Generally speaking, is there a significant enough difference in the quality of the products offered at each of these stores to warrant the significant (2X, in some cases) price difference?