what it is worth, depends...
...on the current price of steel scrap. Just kidding (sort of). I have used one before. It worked okay, but not great by any standard. Probably not any more inefficient than my Schrader that I heat my shop with.
Yes, the newer stoves have a better cleaner burn to them. Sometimes I just want to get a ton of heat in a hurry. If it is close to 0 outside, my stove pipe is probably running 500 deg :hmm3grin2orange:
1200 sq ft shop somewhat drafty doors and I use 4-5 cords of pine a year heating it 3-4 days a week. I don't consider that to be too awful bad.
Low ball him on the fisher, see if you can get it cheap.
-Pat