I like the idea of this, and I'm sure you save a lot of money, but the downside is this: I want to do some one-off job I haven't done before. It'll be difficult, because I will be trying it for the first time. Do I really want to make it even _more_ difficult by cheaping out on tools? I've done this several times, and I've ended up doing several jobs over again with better tools after I've screwed up the first time.

Edit: In other words, cheap tools aren't just less durable, they often do a worse job (or at least make it harder to do a good job).