Cost of living for the next couple decades so I am free to work as much or as little as I want, on whatever project interests me, without bothering about contract work to pay the rent.
Dat ticket to Mars tho
The cost of living will be more expensive in the next few years to come and because of that. The best way to spend your bitcoins is by starting a business that will give you a passive income. In that case you will be able to have a stable income sustain your daily life.