See the revision here.
This was the old version...
No bucks, no Buck Rogers.
We've already identified our goal, $10 billion. Some billionaires have already indicated a willingness to contribute as much as a billion themselves with nothing back but the knowledge that they've made colonization possible, but we can do better than that. We sell mars!
Mars has 144 million square kilometers of potential real estate. That's 14.4 billion hectares, so 10 billion hectares at $1 each would do it. We set up a trust that anyone can contribute to. The colonist will buy land from the trust for their use on mars by the square meter. A hectare has 10,000 sq. meters. So just 10 cents a sq. meter would be $999 profit per hectare to the trust contributors. We choose the lucky winner by lottery. The more hectares you buy, the better your chances. Unlike a normal lottery every hectare is an eventual winner.
The more colonists that migrate the more the land will appreciate. Once living on mars is demonstrated and every colonist arrives a millionaire the pace should pick up. Land is limited so everyone (or their heirs) is guaranteed to eventually make a profit.
Furthermore, unspent interest each year could also purchase hectares at $1000 each (about $20k is all that is required to prime the pump for an annual winner. $240k gives us monthly winners.) So assume we've accumulated a million dollars earning 5% or $50,000 annually. That would trigger 50 lottery winners. The property would remain in the trust (not specific to any location) and would not participate in the lottery. It could be sold to speculators after all $1 hectares are sold.
Once the $10b is fully funded, we allow speculators on earth to buy land from the trust at a penny a square meter with a lottery determining who gets the $100 (Or we just set up a bid/ask market place.)
Update: Checking the Red Lander wikipedia page I had to revise the lander specs because it was 1,500 kg heavier with 1,500 kg less payload than I was using.