I built a sset of tracks for my 5300JD a few years back. Only cost me a day in the shop and about 300 for steel. They work great. although they don't have the rollers and a long tractor to ground area, they still get me around well. I initially made them to protect the tires from punctures. I was mowing some hawthorn trees and the tires were taking a beating.
What I did was take channel iron, cut it to the length of the tire width, weld a three lengths of chain, one length to one channel, one to the other with one in the middle so it could hinge. I made it long enough to wrap the tire while deflated, bolted it together and reinflated. used 8 inch channel for the rears and 6inch for the front. No more flats and I can tell you that I could go anywhere I pointed the frontend
They did enhance the floatation some, but I can see that they wouldn't make it in deep snow. But for my needs they were thousands less and worked well.