I have a petsmart near me that during the day time on week days has a very good staff. And there is 100's more around the world that has very good staff. But the thing that kills me is when they sale stuff in the store that MIGHT not be a good idea.
Whent to a LFS (mom pop store). And seen a piece of driftwood. Ask the owner if it could be put in a fish tank or if I needed to do something to it first. I was told no just rinse it off with some water and put it in there. So seeing that is was alot cheaper than I could even find in any other store I got it. Got to car and started reading the tag (dumb I know sould shop in the store not in your car). On the tag it read WARNING not for Aquariums, not to be used in fish tanks can be toxic to fish. So I took it back into the store to get my money back and the guy even after reading this told me no cash refunds on clearence, then stated telling me lots of people buy these and use them in fish tanks and in all other kinds of water set ups. So I ended up trading the driffwood back in on some food.
So I guess what I learned is that you should have a idea befor you buy.