I made an interesting observation last year regarding Lowe’s, and it just might apply to Home Depot as well.
I bought some tomato cages at my local Lowe’s. A few days later, I decided that I needed a few more of that item, so I purchased them in a different Lowe’s store ~20 miles away while I was on the road. When I compared receipts, the identical items were priced something like 30% cheaper at the more distant store.
Thinking that I had just missed-out on a sale price at the local store, the next day I returned there and–sure enough–that item was still priced ~30% higher.
So, apparently, there is regionalized pricing–even within a fairly small mileage radius. And, the strangest part of it all is that the difference in average household income between the two towns is really negligible.