I've done some basic math and since it is approx 43 percent increase in cost to upgrade an S from a 70D to a P90D, I calculated that a Ludicrous 3 should cost about 15k more than the base 35k starting price ( 50,000 without options ). Now, I'm allowing myself a guilt free budget of at least $7,500 for upgrades since I will hopefully get the tax credit ( I was first in line at my tesla store on reveal day) , so now I'm asking myself , would I be willing to spend just 7 or 8 thousand more and have a Ludicrous model 3 but forgo the options I want ( leather seats, high fidelity sound system, supercharger access, full autonomous mode upgrade, and 20" wheels) ? Right now I'm thinking I'd be willing... feasibly I could upgrade most of those other options at a later date.