Thankfully in my area, my LFS' prices are generally more competitive than Petco and I see people at my Petco looking at fish, but I have never seen anyone buy Saltwater fish from there (mostly supplies and other pets). My LFS in the area all appear to be doing well and making plenty of sales on the other hand. Then again when you see higher prices, fish with faded colors, fin rot, covered in ich, etc. then it isn't much of a contest when even a novice can see how bad they are. It also probably doesn't help that Petco's live rock is literally more bristleworm than rock.