Lol - this is too funny. I suppose not every Petco is bad but I don't go there looking for knowledge either. I'm lucky to have access to a few nice LFS close by & 1 in particular will not give out bad info to make a sale. I plan on getting livestock from them once I get my 28 going, everyone here buys from the same wholesaler anyways so unless I want something fancy it works or I'll go to Old Town.
As far as feeding dogs goes, the good food is never cheap no matter where you shop. I don't think Wellness dry ever is on sale & the cans aren't enough of a discount to make me do cartwheels. You want to feed a good diet - look at the ingredients on the bag. Your protein source should be first on the list & it should be Chicken/Turkey whatever not followed by the word meal. Don't buy anything with BHA, BHT, or Ethoxyquin in it, they all cause cancer. Flint River Ranch & EVO are both excellent foods, but not cheap. I work at a veterinary clinic a few Saturdays a month & you couldn't pay me a million dollars to ever feed most of the prescription diets we carry.
I just put down my Border Collie / Sheltie mix a few weeks ago. She would've been 16 this month & I haven't fed anything except raw food since she was about 4 or 5. You want to know what to feed or avoid just PM me.
PS - I like to go to Home Depot, there's nothing like being the only chick in a hardware store to get attention