Bangkok to Eastern Europe by railway?

I heard their is a railway line from Bangkok to Istanbul (Turkey) called the Trans-Asian railway? How much would this cost? And how long would it take?
Please no people guessing. I would like realistic answers from people who may of done this or have some idea! thanks.

both cities are connected by rail - but with a lot of change overs - for the leg from bangkok you can get rates and duration from here: http://www.orient-express.com/web/eoe/eoe_a2a_home.jsp

another source is:

http://www.railserve.com/Passenger/Asia/

hope that helps