One i seen for sale is made just like that.but yellow and asking $650.00 for it.is that to much for it?.
You have to have a look at the flails. That will determine how much you will spend to get it in good condition to mow. See if it has the "Y" flails or the wide solid flails. The solid flails are needed if you are going to go over brush larger then an inch or so. The "Y" flails will mow a field, and look like you mowed it with a Lawn Boy push mower! I leave my flail mower up (more then most say is possible) and they mow fine and leave 8" of grass for cattle to graze.
To answer your question $650 is a very fair price for a working flail. Check out the condition of the flails, take the cover off the one end and check the belts. Look at the grease fittings, at the PTO shaft, each end of the roller, and at the shaft with the flails.... mostly to see if it looks like they been greased in the last 10 years!!! Oh, be sure to measure the length of the thing. The guy told me he had a 6' flail, when I got there it was a 5 footer. We agreed on an adjusted price and I bought it.
A side note. If you get one always run it at 540 PTO speed. If you do not it will not pull the grass up and cut it the way it should.