Yes, PLEASE get a new tank!
Your betta will be so much happier and you'll be able to see him swimming around comfortably.
There are gold fish starter kits at Petsmart for $20, I think they are 1.77 gal which is still not ideal but so much better than what you have.
They are really nice looking and come with gravel, filter, background and a plant! They come in different colors. There's a bigger one for $24, I think it's a little over 2.5 gal.
Same price at the store, just saw them this week :D
Good luck with your search!