Cant decide 5ga or 10 gal need input.

[Hobgob]

Actually, you can buy a 10 gal at Walmart for like 12 bucks. 10 gallon is good for if you want to have a lot of fish and want to breed, well that's what I bought one for. I quickly outgrew a 2.5 gallon but I am keeping it for when my fish lay eggs

A ten gallon is not a breeding tank... 20g breeder is. Also I wouldn't use a 2.5 gallon for a nursery/rearing tank. Use at least the ten for that...
And where do you live? 12$ that's like petco $1 per gallon sale...

Also make sure the kit includes a heater...