It is interesting how a new project usually means that you need to buy a new tool. I've been down that road several times myself. I actually read an article a while ago where they were saying if you are going to use the tool frequently, splurge for the higher end version. If you are only going to use it once a year, then get the cheaper model. Over here at Home Depot they also have a tool rental service which is kind of cool. You can rent anything from a dump truck or plate compactor to a battery drill or table saw. In the long run it is probably more expensive for some things, but it might cut down on the waste too.
We have the same, hire tools, plant and equipment which is a good way to go for some. I prefer my own stuff though and do enough DUY to warrant the cost of most things. I've actually paid tradespeople to do jobs for me when I've determined the cost of it to buy is too high (and future use of the equipment is not there.) I rarely do the cheaper tool though though, however it's been known to happen now and then.
My buddy owns a handyman business, so whenever I get in over my head or I need a tool I don't have I usually just call him up. I think it drives his wife crazy, but he has known me longer than he has known her! :)