Pet Solutions is a LARGE online / catalog pet supplies retailer. They also operate a chain of stores in Ohio called Jacks. They are most definitely a retailer and not wholesaler. I took a quick look at their live stock pricing again today and while their prices are still high IMO, but they are significantly lower than I remember a few years ago and not completely out of line retail prices.
Grizz, keep in mind Skis location. Not much available in Alpena area unless its shipped and there aren't many options for shipping on a wide assortment of fishes at the same time. One place may have africans, another tetras, and yet another something else. I'm sure that is one bid draw of a place like Pet Solutions.
In regards to quality issues the difficulty is you have no idea of their source and lineage of the fish, which is why I've now only buy specific fish from specific sources. But it takes a while of being in the hobby to figure all that out. I.E. buying a neon tetra from big box pet store is okay, buying a Hap from a big box is probably a waste of money due to quality. It is a learning experience everyone goes through. Just like the learning experience I'm FINALLY getting about being cheap and buying fry versus adults. Fry end up costing more than adults because of the electricity and food need to raise them.