I've also thought about buying a lift, but after renting them, I've learned that I don't really care for heights, and I don't want to maintain it. Going to town to rent them is the biggest waste of time, but for the few times a year that I've needed one at my place, it's proven worthwhile. Home Depot rents a 35 foot towable lift 7 days a week, so when the other rental yards are closed, I go there.
Getting the towable unit into the "perfect" position usually takes me a few tries. Then setting it up, getting up there, and then coming back down and moving to the next place all takes time. If you only have a couple of hours a day to work, you will get very little done. So renting doesn't make a lot of sense. You'll be spending all your time going back and forth renting it.
Are you up to maintaining it and repairing it? The less you pay for one, the more hours it will have on it. Just like buying a used tractor. Buy cheap and spend all your time wrenching on it.
I've seen better deals on service trucks like what the power companies use. Not as much lift, but plenty for just one guy and a chainsaw. You have to maintain the lift and the truck, but if you are just driving it around your land, that shouldn't be too hard.
Do you really want to be up in the air, cutting branches off of trees with a chainsaw?
As a contractor that does everything myself, I have hired pros to come in to take out trees that scared me, and remove branches that I couldn't get to. Sometimes it's a lot cheaper to pay somebody else to do it then risk the medical injuries that you might receive doing it yourself.