Agreed with Young Coder, You get what you pay for.

I own licenses to both vBulletin 3 as well as IPB 2.0 and have tried them both out. vBulletin is, in my opinion the best Forum Software out there (as of yet).

I suggest forking out the extra money for a vBulletin license, in the long run you will be more than happy...at least me and thousands of other people are!