I think some of the problems of buying new fish comes from "common names" versus ""Latin' names" & now newer names too. Sellers are often shipped fish by a common name, so that's how they sell them. They don't or can't attest to the truth of those.
& some names are similar that are especially confusing to new fish keepers. Red tailed shark vs red tailed catfish are very different but both cute bottom fish at a very small size. How many "rummynose tetras" are there now? More than the 1 kind when we started in the late 70s/early 80s. Even more now as new species of many genera than were ID'ed than sold back then. I know some fish well enough to see they might be different from what I expect, but there can be individual variations due to age, gender or variety.
I ask questions then research as best I can before buying. Not many newbies do that or know they should. They have to believe someone, often a lfs employee. I once saw young zebra loaches I had wanted in a Petco. I asked how much they were & was told they were yoyo loaches, $1.99. I said no, here's a pic in a book they sold. Well, that's how they're listed so that's how they sell them. I bought all 6 & checked to make sure b. striatas were all the same in the bag, all they had.
I also sat on the wet floor while the slightly snobby/scary lfs guy & I looked up what kind of new loaches they had. He knew me as a fussy older fish buyer that knew her stuff, more or less. We narrowed them down & I said I'll look them up online. I ended up not getting them, but I greatly appreciated the attention he gave me & he liked helping me too. It pays to make friends of knowlegable lfs employees.
At another I would ask what new loaches they had, then catfish, then browse other fish. They knew me too. Not a frequent buyer but that I liked oddities unlike some others.
So, I guess I'm saying buyer & sellers could both be more aware & helpful with research. I tend not to take any 1 source of info as truth, but give them the benefit of my doubts...until I learn differently from what I consider reliable places. I have a LOT of patience waiting for what I want, lol.
Unlike 2tank, I run out of patience helping newbies cycle sometimes. Pick 1 & go with it, any way can work...eventually, but they have to stick with it. His preferred way is not mine, usually, but he beats me on the patient step by step help
