I wouldn't do it. 2 gallons is awfully small for neons and a betta. Those neons are just going to end up dead... that's a waste of money in my opinion...40 cents a fish or not. You could use that little bit of pocket change on something else more useful.
I'm amazed at how cheap they are by the way...
Dijon: Blue mustard gas hmdt plakat male
Little Girl (LG): Blue crowntail female
No name yet: Purple/pink/white delta tail male
No name yet: Red and silver halfmoon male
RIP Storm, Flair, Marina, Flash, and Sterling... I miss you guys so much :(