Don't run out and buy tools before the need for them arises. Many components change and the specialized tool changes with them, so you might be spending dough on something that might be useless before you ever use it.

Also, I'm 100% of the philosophy that it's skill and not tools which define the mechanic. Develop the skill set to do a job, then decide if you want to invest in tools to make it easier.

A classic example is a wheel truing stand. Wheels can be aligned in the bike using the brake shoes, or ice cream sticks and rubber bands. A stand makes it slightly easier, but probably wouldn't be cost justified unless you were aligning wheels on a regular basis. I've owned a truing stand for almost 40 years, yet end up building and aligning wheels without it because so many are done on the road.

Over time you'll make a personal decision as to where to draw the line, in some cases because it isn't worth your time, in others because expensive, highly specialized tools are needed and can't be justified for limited use.