There was a local shop here that sold bettas in any little jar that he could find. Some of them were so confined that they couldn't turn around. I felt so bad for them. I refused to buy anything from the jerk.
Those aren't to bad. I started with the Marina Betta *Pals* Kit. Totally different, same water size, but more wider than high. And it comes with a plant for more security in the fish.
The worst "Betta tank has to be those fish I pod things! I hate them!
Those are pretty bad, but I'm telling you, this jerk had a fish store in our area and he would sell bettas with these tiny vases that were so small that the fish’s nose would touch one side and his tail would be touching the other. They would be about 5 inches deep. I felt like buying all of his bettas but I knew that he would just buy more. Plus he wanted like $20 for the fish with the vase. Guy was.... well, I can't say what I really want to say on here. Thankfully, he has finally gone out of business.
I feel ashamed but I had my fish in one of these when I first bought him. After a little research I quickly bought a 5 gallon and now I'm waiting on my 10 gallon to completely cycle and I'll be switching him over to the 10 gallon. It's crazy because that bowl is the size of a log ornament in his tank.