Was wondering if anybody has a website or such where he/she buys dirtbikes?

My friend's active within this and I'm searching for a decent website that's trustable to check prices around the net
Currently found this..
.. which is what I might go for, but I have no idea whether this is a trustable site and such.

My friend helped me with searching around for bikes already, so I'm now searching around for more sites where I can buy one.
Anybody who's got a trustable site which sells proper ones..? :P