cody stay clear of it is my advice
yeah the blasters are a nice little bike and they will go some..
if he is selling it 9/10 there is somethink else wrong with it..
ask him to sort the head gasket out as you are intrested in it but not as it is only if its problem free
you could also ask him if its ok if you get the bike professionaly checked over see what his reaction is to that .. that will give you a good idea if nothink to hide he will allow you..