I am not a woodworker. My first attempt was to build a unique tubular sealed sub cabinet. I spent around $300 just for the tools I needed: router, router bit set, circle jig (which I broke halfway through the job), circular saw and blade, 8 clamps of varying sizes, glue, sandpaper. I got it done with a little help from a buddy but it was not pretty.

I ended up selling the circular saw though I still have everything else in storage. I did use the clamps again when I glued the flat packs for my OB subs and Super 7 monitors.
I prefer to have someone else cut the cabinets.