I like the idea that those taking the risks should get the rewards. But there just can't be a fast enough rate of new colonists to make my initial plan work. Which means the risk is just too high to get any banks to finance new colonists. So perhaps we can shift the burden.
I still want to see every individual going to mars getting a claim. Actually, I'd like to see them get a sq. km. claim when they land and a new one sq. km. claim every two years they live on mars. The transport company gets a 1000 sq. km. claim for every colonist with supplies they deliver to the surface of mars. The colonist picks and pays for their own supplies (1000 kg?) but the transport company pays for the delivery to the surface with the colonist.
Each sq. km. is surrounded and separated by a perimeter road. Each claim is theirs and they can sell it off as they like but I've determined they can get 86.4% utilization and a minimum of 40m of frontage road for each of 432 plots of 2000 sq. m. each (40m x 50m) which could each have a 40m Zubrin hobby farm (feeds two.)
So the first company to deliver 12 researchers gets a claim of 12000 sq. km. When they follow that with 3 dozen more they get an additional claim of 36000 sq. km. Follow that a few years later with a hundred colonists and they get another 100,000 sq. km. claim.
This would insure the colonists share in the wealth and also have no transportation costs that would prohibit them from arriving in the first place. This also takes off the pressure of having to have a specific rate of colonists to support the initial colonists and all those that follow.
Update: So if this transport company delivers Elon's 10k colonists with supplies to the surface of mars they would claim 10,000,000 sq. km. which is actually more than the settlement initiative would offer them. But they wouldn't be able to completely take some prized region. Other companies would have a chance to compete for those during the same time.