With the ways things are going owning land is fairly outrageous when you look at the prices. I have been trying to think up a idea that might work to make land affordable to all players.
Here is was I was thinking up... It would be to create a land mass with small parcels at first, like "first land" set it to first land prices. The catch is that the land that is bought cannot be resold or transferred to another person, you would be able to abandon it and lindens would reclaim it and put it up for sale at a random time. This would prevent people from trying to resell it to others by abandoning it and trading it for lindens by to someone else quickly.
At first maybe limit this to 512m per account. As a experiment. If it works out maybe it can be expanded to owning more parcels but not being allowed to join parcels together or split them up. Eventualy the land in Second Life would be divided up into land that can be resold (Unrestricted Land) and land that isn't. Basicly its for rent from Linden Labs (Restricted Land) by paying your tier fee.
Only exploit I can think of are people trying to rent out the parcels, Should make some rules against this. If other plans are in the works would love to hear about them!