they are not a real powerful car even being turbo. 117kw from factory...
the gearboxs in those are a real weak point. i know someone with one and he has had many problems with the box after he started increasing power. so good the transfer case has been done already. thats half the problem.
i would have thought closer to 6-7K price wise seeing as the ****ty stock ones go for about 3-4, like scort said though, depends if it is done well. seems like someone has thrown a bit of coin at it.
good luck. i do like those little cars, they look like a lot of fun.