I'm probably into mine about $5,000, including the $1500 purchase price. Electrical was over $1000, and then I have a laminate floor inside, and mostly knotty pine T&G walls. I could done it cheaper, but there were some things that my wife wanted a certain way, so I spent a little more to keep her on board
. That also includes over $500 in bus maintenance. This does not include the A/C or a 5000 watt onan generator that I traded some stuff for... I think that even with using craigslist, ebay, bargain shopping, etc..., trying to do a conversion without cutting any corners, or at least as few as possible, for less than $5000 would be very difficult.