I paid for EAP and I paid for FSD. I would do that again. I would do it again for several reasons...
I believe in the mission and I'm happy to support it.
I bought a lot of Tesla stock at $17 and, at the time of purchase, I had enough to buy my Model X in cash. But instead I financed it for 6 years at 1.99% and left the money in the stock. If FSD comes out after 3 years, I will have paid about $1,500 for it by that point. If YOU want to pay cash then, you will have to pay full price (unless you go borrow the money elsewhere I supposed.) In the meanwhile, most of my money has been invested, not paid. If it comes out, much of my money will remain invested until each payment comes due.
If the price of FSD goes up -- and I think it will -- my price is locked in.