NASA has a $500m annual budget for mars. If I got the job...
$100m prize to 1st and 2nd private company for 2500kg payloads each delivered safely within 10 km of a specified point on martian surface. Must accomplish before 4th year prizes are awarded.
$100m to 1st company to put ship in LEO meeting these specifications: Refuelable in orbit, 13 ton ship w/ life support for 12 and 240 m3 of internal volume. Must include storm shelter for solar flares and capable of 6 km/s of delta V after refueling (assuming dry departure mass of 40,000kg.) Ship remains owned by the company that put it in orbit.
$200m for 100,000kg fuel stored in LEO which could be transferred to ship.
2nd year: $500m for additional fuel to LEO.
3rd year: $500m for five more supply landers on mars. (17,500 kg of supplies now prepositioned for the first dozen colonists when they arrive.) Supplies will include radio controlled rovers with 200 km battery range pulling trailers with seating for six and inflatable tent. Solar panels to recharge and really small methane engine generator for backup.
4th year: $500m for six, 2 crew, 2,500 kg payload landers put in mars orbit. Unmanned craft must have successfully demonstrated landing on mars which would likely be one of the seven presupply missions.
5th year: $500m for transferring crew to landers in mars orbit and getting them to the surface. Ship still belongs to private company and they can do what they want with it after crew transfers off.
6th year: Embezzle and head for Rio. Set up mars land title company.