I've been out with my brother in law and mechanic friends to a lot of swap meets over the years. Every now and then, I'll find a tool I need, or think I may need. Most of the time when my brother in law saw that, he'd always say; "Don't buy that, I have one, you can use mine." Our mechanic friend then always tells him; "yes, but this way he has his own". I just tell him I want my own so I have it when I need it, so I don't have to run back and forth to get and return it. Suppose he's not home when I'm ready to use it. Then I'm stuck and can't do or complete what I'm doing. Much nicer to have your own tool, special tool or not.
Usually my 16 foot extension ladder is sufficient to do what I need to do around the house. About 20 years ago I needed a 24 foot extension ladder though. I could have rented one, but.........wasn't exactly sure when I'd have the time to do the job, or how long it would take due to having to do other things. So.......I just bought the 24 foot ladder. Used it for that one job, then it hung on the garage wall for the next 10 or 12 years. Then my son needed a 24 footer to do something on his house about 8 or 10 years ago. He borrowed mine. Told him he could just keep it at his house. If I need to use it again, I know where it is. It's still at his house. Looks better there than it does at mine taking up space in his garage.:D