Maintenance costs/most reliable scoots

[KLR]

A dealer near me has a low miles 2008 Burgman for cheap but the clutch slips when you get going - precisely how fast they didn't say but it sounds like the thing needs replacing, so throw in a grand on the sticker price if I have it done or maybe $600 if I get under the hood myself. It'd be nice to have a freeway ready scoot bought on credit (I don't have tons of cash lying around at the moment) but having to replace a major component right off the bat is a pain.

This got me to thinking - what are the annual maintenance costs for scoots? I've read a bit at motorcycle forums on this; generally speaking it sounds like cars need a ton less TLC than 2 wheelers, for whatever reason. And what would you guys say are the most hassle free makes or models out there? I've read how 2008 Burgmans had shoddy clutches, for instance...do smaller scoots require less upkeep than bigger ones, too? I think I'd be happy with 250cc.