I did it in stages as I needed but I have lots of tools in my guitar repair business so that helps. I got a shimano lockring tool, then a chainwhip ( can make them yourself too), then I bought a park truing stand, park bottom bracket tool for external bearing bbs but can work on others too. Then when I went to build my own wheels I bought a park tension meter, spoke wrench 4 sided, and I already have huge number of measuring devices that helps. I have a micro meter already, assortment of measuring calipers and steel rulers. I went on the idea that if I was a serious rider I wanted to be able to work and fix my own bike and there is some money but this way I rely on myself. They charge for tune ups and the like at the LBS and I can do them, the next step is to somehow do a few for others as a payback. I did go with the idea I would basically work with shimano parts and this helps narrow it down. I now need a cone wretch but really will not use it much. Then of course the usual things like a chain tool, tire levers, and I keep spare parts around. Nice to have a replacement chain, tires, tubes, and brake/derailler cable and housing ready if you need it. I bought a huge roll of housing and cable this is much cheaper in the long run. I avoid tools for bikes I do not ride since some bikes require separate tools for each type.