It's also worth stating that in many cases, restoring an empty cab from scratch can be more expensive than just buying a complete and working game. Lots of small parts can add up. Plus there's the question of how much is your time worth?
There's nothing wrong with a bare-cab restoration, and you'll likely get more satisfaction out of doing one yourself (if you enjoy doing that kind of restoration work). But just be aware of what you're getting into up front, and know that you don't usually end up saving money going that route.
This hobby is a lot less expensive if you get into restoring whatever games you can find for cheap, close to you. Some of the most fun games can be ones you've never heard of or played before, that just cross your path randomly for cheap.
But if you want a specific title (which is fine), you either spend money to find and ship the right cab, or you patiently monitor all sales channels (Craigslist, FB, ebay, here, etc), and wait long enough for one to pop up near you. (And have the cash and vehicle ready to jump on it when it happens.)