Firstly welcome to the yard!
Well established posters/forum members at Blade Forums or Knife Forums should be pretty safe to buy from.. I got a Busse Basic 7 that way off BF. What I did was posted a 'want to buy' ad' on BF then checked out the repliers on 'The good, the bad and the ugly' thread. I checked out the feedback on the feedbackers too, so I knew it was all good (well as good as I could make it!). It still felt like a leap of faith at the time, but it was fine!