Also depends on how far you want to go DIY. Chain cleaning and change out and cable changes are one thing, crank pulling, BB R&R, cassette R&R are another as
their have been a series of evolutions here needing new and different tooling. If you have a variety of bikes you likely have some with sq taper BB, some with
the variety of splined. Some chains have master links, some don't: different tools. CW fixing bolts can be hex or torx. Freewheels need different tools also.
All my crank pullers are useless, as none of my cranks now need them.