That's a very good looking rotary cutter. As you undoutedly know, cutters like this come in at least three grades - light-weight, medium-weight, and heavy-duty. That looks to me like a medium-weight machine. I'd be proud to have it on my rough, hilly, overgrown farm. I believe that you could easily use it on saplings up to 2 inches in diameter.
Here in Middle Tennessee, I think that you could acquire one like that for $600 - $700.
Good luck with your decision.
Tom in TN