I got a large older stereo system with cabinet and surround speakers (2 larger, 3 small) from my inlaws for $50. Thought it was a steal for the garage.......then I spent $140 in speaker wire...lol. Its a pretty good setup now so i'm not too upset.
I had to do about a 50 minute drive home with mine standing in the back of the truck. Mine was on a tiny little pallet so it was about 5" taller. Not an overly good feeling having them standing up like that...lol
I am going to guess you will never use them. Especially over 2" as you mentioned. As a Millwright I have used some big sockets and wrenches but can't imagine you will find much use for them outside of industry. I have up to 2" at home and never use them. You mentioned working on tractors...
I had a small bench model which came in handy now and then. I upgraded to a good size floor model and find it to be 100 times better. I use it more and it works much better!
I have no problems with helping a good friend out and letting them use my lift (likely supervised) but a friend of a friend is pretty much out of the question.
You should buy shallow and deep in all 3 drive sizes. Semi-deeps are something you should look at after as an add on if you feel they would be helpful.