haha a used car has about 1,000 times as many moving parts and little pieces of low quality junk that break all the time. Pretty much every part on a high end bike is quality and made to last 5-10 years with a little maintenance. I'd never buy a used bike that was more than a year old, both the ones I've gotten have had maybe a month of riding on them max.
My first specialized enduro from ebay had been on maybe a couple trail rides, everything was mechanically perfect and I got it 1,000 off retail (paid about 1875 shipped vs. 2800+tax). Only difference was the most minor of blemishes on the downtube. The second one that I just copped off ebay is one model up from my old one, got about 1800 off retail (2150 shipped vs. 3900+ tax), so actually close to 2,000 saved. Took it to the bike shop, told them to get it in perfect working condition, now it's good as new. Oh and all costs for maintenance I deferred to the ebay seller because the bike was advertised as like new, it just needed an hour or two to be polished off.
Theres tons of motherfuckers out there that think they need the dopest bike possible (like you and me) but then some life event comes up and they gotta ditch the excess. ebay is littered with basically new bikes that the owners never got around to riding much and decided they needed the cash for their new baby. I doubt I'll ever buy a new bike again given how insanely high the prices are getting. Everything just went up like 15-25% across the board cause of increases in component prices and the failing u.s. dollar. can't hurt to do some research and find out whats available, i know you've got time!