Personally I think your best off with a nice looking pastel. Nice snake to look at, and affordable. Really good for a pet -
And you can breed it into anything in the future. Being co-dominate You'll end up with visual offspring regardless of the pairing.
And in your price range you can probably pick up a female (which I would do if you have future plans for breeding).
Yes males have smaller caging requirements but males can breed within a year, where as you need 2-3 years for a female to be sexual mature.
Good Luck!
Cheers,
Chris.