Told you I'd seen it on eBay. I never forget a bike.
Every scam of this type on earth has one common element; the price is too good to be true. In your case, it may have been incidental if you don't actually know the market for this model but it's still present as a factor. It would be like an early 911 coupe, complete and in highly restorable condition for $20k. Something is fishy right there.
The true market for that model is in the teens for a decent original or restored bike and up to $20k for a mint original. Here is a nice restored bike that will fetch mid-teens:
BMW R Series | eBay