My betta fish

[CarpCharacin]

They are very cheap! For me, the tank, the plants, the fish, the rocks, the food, etc. For all that It only cost $27!

I'd recommend a minimum of 10 gallons for a betta, but you can get those for like $10 at the Petco dollar per gallon sale. In the past, I have kept bettas in smaller tanks, but I think 10 gallons is the best size for keeping the temperature stable. I think it's a bit difficult to regulate the temperature in a tank smaller than 10 gallons, and temperature fluctuations stress out the fish.

 

[cluckmecoop7]

Well, you might be right.

 

[CarpCharacin]

IMO 5 gallons is the minimum water parameter wise, but it can be difficult to maintain a consistent temperature in a water volume of that size.