While I have a sizable investment in tools, for the repairs done in the OP, we are not talking a lot of money. A couple of cone wrenches, a spoke wrench, cable cutters. I bought an RD hanger straightener off ebay for less than $30, so that is not too bad either. But unless you are going to do quite a few repairs, I would not bother with that one yet.
I find it cost effective to just buy a couple of really good tools first, along with tools that fit your current bike (a lot of stuff is not standardized on a bike). As you do more work, expand your tool collection. In the meantime, you will need to find a good LBS to do the more technical stuff.
I have bought at least half of my tools used, and have upgraded over the years. If you buy right used, you can usually sell the tools off and get your money back out of them when you upgrade. I have upgraded my work stand (multiple times), truing stand, derailleur hanger tool, chain tool and cable tool. Old cable tool and chain tool broke, so they ended up in the trash. Other than the chain tool, my other upgrades were all bought used.
Last edited by wrk101; 06-13-11 at 07:29 AM.