I would definitely take the $3k and run. I can't see too many people using more than $3k worth of supercharging over the life of their car. Heck, I've only spent $109.64 in the 1 year I've had the car, and that includes several road trips. All in all, about 10% of my kwh come from supercharging. If I ONLY supercharged and never used a destination charger, I'd be at just over $1k in supercharging costs in a year, which would take me ~3 years to break even with usage remaining the same.
As for FSD - I'd pay for it when it gets here.