Originally Posted by Lord Vetinari
A male common boa should be ok in a 4x2x2. I have a male thatís 4ft, he's a good feeder but just doesn't seem to grow. But thatís a rarity - you really have to expect them to hit 6ft so he may end up looking a bit squidged in a 4ft viv. Dwarf Boas are smaller, but you may struggle to get one on your budget. I'm not sure though, I'm not too up on the pricing of dwarf boas. Sonoran boas are very pretty though.
If it's useful, when I was at the Creaks show in December there was a breeder selling dwarf Sonoran boas at £65 for males and £75 for females - this may be an unusual price (ie because it was the last show of the season) but perhaps worth FloGirl keeping in mind if she's shopping around to get what she wants without paying the earth.