I have a JD 5210. Rating is 45 pto horsepower, I believe, but it is a medium sized tractor, not a compact. Cat 2 hitch. I struggled with the 42 vs 62, finally bought a BX62 and I'm really REALLY glad I did. It is NOT too much machine for my tractor. My tractor doesn't even strain when I shove through any live branch that will fit. I could go on and on but that would be off track for your thread.
You know what they go for new, and if it is like new, I'd think a few hundred less would be reasonable. You can see pretty readily if the knives are perfect or worn, etc. These are well built and should hold up for a lifetime if properly maintained.
The BX 62 is several hundred more, but is a lot more machine and if you can afford it, you should consider it. Just look at the weights of the flywheels and the weights of the whole machines to compare.
I haven't seen anyone post regrets about purchasing their BX42, however, so if the right deal presented itself, buy it and you'll probably be happy. Use a chainsaw to cut the bigger stuff for firewood, as many have suggested. Your bigger tractor will not hurt the smaller
chipper any more than a bigger
chipper will hurt a tractor on the lower end of the suggested size provided by Wallenstein.
Let us know what you decide.