if i was gonna do it all over again i'd deffinately go for a 4x4 but there's no chance of me swapping mine now cos i love it too much
2wd is useless in the wet to say the least, got beaten by my mates RS2000 the other day on roundabouts etc.
basicly i'd say when buying one spend as much as you can afford but make sure it's got concrete history to back up the price. no point spending 3k on a OK example thats going to need rear arches and a engine rebuild in 6-12 months time.
check all the usual places for rot. inner wings, boot floor, chassis rails etc. don't forget even the latest sapphs are 12 years old now.