Is it worth it to you? We have the 6100's little sister, the B5100. At 12hp she still pulls like a little bull. What would you want to do with it - I guess that's the more important question? If it doesn't disappoint you because it can't perform like a BX, then maybe you've got a good fit at a reasonable price.
I can tell you that it will sip fuel, compared to anything that can pull as well on the market today. Maybe not much of a distiction now, but if we ever end up having to wait in line for fuel it might be a real deal maker for you.