OEM parts can be really expensive, but there are also choices of buying aftermarket ones (mostly made in China) or salvaging from another ones. Near where I live there is a guy who salvages Land Cruisers for a living, he has more than hundreds frames lying around in his yard. Since most of the Land cruisers here have 3rd world spec (carb-ed and detuned engine, part time 4WD, mechanical gas pump etc...), the used parts are often in very good condition. Take the dreaded blown head gasket for example, I rarely see that here because 1FZ-F doesn't run as hot as 1FZ-FE. Or the Birfield, most people just run on RWD mode so they are often pristine.

(of course for something critical such as brake booster I would only use OEM).