My reasoning with the multimaster tool is:
1. The $40 clone from Harbor freight is so cheap that I won't worry much if I either lose it, break it, rust it because of little use, or find it doesn't have all that much use after all.
2. It allows me to try what it will do (and what not).
3. If I find it is useful, and it holds up, I win. Cheap, useful tool!
4. If I find it is useful, but it starts falling apart, I buy the real thing, I win, too. Because for just $40 I got to try it and learned I want it.
5. If I find it useless, I lose just $40.

I'm at steps 1-2 at this time. Haven't used it all that much yet. I'll have to wait and see.