Just my experience, when I started purchasing more than the basic bike tools, just buying as needed worked fine. I do not have to be in a hurry. I gathered info from this site and others, like youtube, parktool.com. I used a couple of self made tools a couple of times, and then wound up purchasing the tool, like a headset press. I recently used that on press fit bearings and it worked fine. Most of my tools are house brand from on-line bike shops. They are working out well for me, lower cost and I only use them occasionally.