Hmm, interesting thoughts.

I originally started on a phpBB forum but found it too complicated (about 5 years ago). Then I switched over to vBulletin and found it fairly easy to use, I learnt a bit doing phpBB stuff. I also tried SMF but didn't like the amount of modifications or styles it had. I never tried IPB until a while back but I guess it is because how much I know about vBulletin and my experiences with it that make me want to stay with it. I didn't find any nice styles for IPB which I felt content with so I guess that was another thing I disliked. It all felt out of my comfort zone.

EDIT: The server wont be expensive unless you're offshore and if you are it's more than likely because you're doing something you shouldn't. Servers from Canada, USA & UK are fairly cheap. I have a VPS with 1GB RAM and decent storage/bandwidth which is costing me 7$ a month.