I'll weigh in on my use of the car vs. pinball machine comparison, tho no economics are involved. I've used these analogies several times when talking pinball machines with my car friends (I've restored both).
Classic Restorations
Both car enthusiasts and pinball enthusiasts can fall into camps ranging from "purists" to "anything goes" and everything in-between. You've got classic restorers for both cars and pins that will repair something broken before considering to replace any part, use only original parts before resorting to after-market, keep the patina of the car or pin vs repainting or repairing any surface areas that aren't critical to the infrastructure, and the like.
RestoMods
Just like putting a modern drivetrain into a '67 Chevelle to make it as reliable as new cars coming off the assembly line, you can do the same with many solid state pins by installing modern PCBs. Playfield blown? Put in a CPR. And just like replacing that worn out, beyond repair body on that Chevelle you can get newly manufactured pin cabs for classic Ballys and Sterns or use well-preserved donors to replace your termite infested originals.
Rat Rods
This seems to be popular in my area....guys taking abused SS pins with lots of cosmetic damage, patina, missing/damaged plastics, and "history" and make them run like a top with new PCBs, rubbers, flipper rebuilds, and the like. Pins plays like new, but looks like it's at death's door.
Over The Top Customizations
Just like the car guy that takes a classic 1956 Corvette and slaps on oversized tires for a lifted rake, paints the body in art deco colors and think's it's beautiful you've got the pin guy who puts clown puke LEDs in his STTNG and thinks the same. There's room for everyone in both hobbies.
One of the better analogies I like to use is discovering that bargain project you bought home has more serious issues than you thought as you start to peel back the layers. Then you've got to make that decision - do I pour more money in it to fix it (if it can be fixed), or do I cut my losses there and junk it or part it out.
The only economic analogy I'll put in is this: The guy who restored his car and the guy who restored his pin will each want too much money when it comes to sell as they "recoup" their "investment". I've been there too many times in both cars and pins - you restore for the love of the hobby and shouldn't expect to make all of your money back.