i bought a mission for £90 of a wee lad from up north last year in feb, and so far i havnt craked it or messed it up in anyway apart form the forks. now im 6ft 2/3" and bout 13 stone of pure beast and im the harshes shitest rider in the world but this bike has suite me own to a tee because its soo cheap it didnt matter if i smashed it up or scrapped it or did whatever to it, but ihavnt had any problems at all with it. and as for upgrades ive upgraded the fors stuk a maggie on the bakc ghanged bars and brakes and stem and alsoconsidered putting a front free-wheel on it (which can be done i just spent the money on booze :) lol). so basicaly my point is mate if uve not got alot of money and you arnt a very good rider then buy it, but i wudnt offer him any more than 150 MAX depending on what condition it is in though.