I want a batta fish! Help me !?

Bettas need water temp. around 76-80 to live happily and tp be healthy. Yes, they can survive without...but not thrive. As to the cost, it can go as low as 25.00 for the tank, maybe 10-15.00 for the heater. If you want it around for some time, a heater is necessary As for a name...wait till you get it and see what's its personality is like.