I initially came to the machining world with almost zero knowledge. I had experience with woodworking, but my metal experience was limited to a year of high school metal shop. Mostly sheet metal, gas welding and soldering.
I became interested in getting a lathe to make scale model parts and after about a year of researching options I ended up buying a Sherline lathe. With the lathe in hand I quickly found a mill would be handy and ended up getting a Sherline mill. Now I was set, I had all the machine tools I'd ever need. After all I was in this to support my model building, that was my hobby, not machining, not machine tool rescue and rehab.
The little Sherline machines were doing the job, but I was just making a few small basic parts. I wanted to grow my skills, to try something more challenging, to expand from the few basic operations I was doing and have to learn more things to complete a task. I ended up buying a set of plans for a small basic steam engine, plans only, materials sourced locally.
That was all fine and well, but some of the parts pushed the limits of my small machines. Cutting small bits of aluminum or brass by hand was fine, but now I was working with steel, and some larger brass stock. Cutting that with a hacksaw got old fast. With the aid of a 25% off coupon the cutting problem was handled with the addition of a HF 4x6" bandsaw.
Soon I met that devil Craig and his list...
I soon had a new hobby related to machine tools instead of just having a couple of tools for a hobby.. I was enjoying learning, and absorbing information like a sponge. I also like having the ability to make and repair things.
With new confidence I wanted a bigger lathe, something that I could use to make the odd repair part for one of my old cars or something around the house. I had also (through this site) found helpful enablers, both online and locally.
I ended up getting a good deal on an 11" Powermatic / Logan lathe. It was functional, but a project. I got it working well enough, I'm still working on tightening things up, an on going game of wack a mole.
With a bigger lathe, I needed a bigger mill. Again my local enablers came through, and I got a nice (not at all a project) Clausing 8520.
Welding and other metal work were added for my old Land Cruiser and fire engine.
I've gained an obsession for small lathes, adding several. Maybe a bit of looking for perfect but that is more of an excuse. Maybe a bit of Pokémon fever (got to catch them all).
The other machines have been more nuanced. A bigger, better quality bandsaw because I've started using my welder a lot more. A small Diamond horizontal mill because it adds some capability (plus it was a deal, in great shape and honestly just a neat piece of equipment). A little Atlas shaper, again it was a deal, and no shop is complete without a shaper.
At this point my machine purchases are a combination, of needs, I like fixing up old things, too good a deal to pass up, and the occassional "I just want it".
There is also quite a bit of an educational aspect, how do I know I don't need it until I've used one. I have a strong personality streak of I have to see for myself. I have lots of life experience proving to me that just because other people think a certain way, doesn't mean that works for me.
I'm still learning, and evolving. My machine purchases are fewer, more directed, and (usually) better informed now.