I've recently purchased a few 10s and 30gs, and small tanks (less than a gallon), so I've seen a bunch of different tanks and figuring out prices. Just be careful as some kits don't always come with heaters - but for tanks 10g and under, the heaters are pretty cheap. Walmart has a Tetra 25w one for 2-15g tanks that works well.. I have a couple that I use with no problems.
lol females can be trouble.. just looked over at my 6g divided tank with my oldest pair and saw the female (Anya) bully her snail down from the side of the tank.. it was in her feeding spot, apparently she was worried it would get in the way come feeding time lol.. poor snail!