Hi Dan and welcome - I recently brought mine from BMW Willsons Manchester (yet to be picked up) used and agree with what others say. For what I've got i think i paid the right price for it (no dealer premium) and got it serviced, 2 new tyres, 12 months tax, 12 months national motorrad warranty and 12 months emergency package and 12 months MOT. don't think id have got that from a non dealer.
if you can afford the time to wait and see what comes up, as hard as it may be, its worth the wait! luckily, mine came up within to weeks of making the decision to buy one.
as for the inherent problems of early models. i can't say for sure but when i was searching for what i wanted my budget was initially for an early one, 2010. while trawling the net for info i didn't find anything that pointed to common problems or failures; I hope this helps
Ant