I also agree that something needs to be done to stop land speculators, but instead of limiting the availability of First Land (or increasing the price), you could limit resell options. What if during the first three months of ownership, land acquired under the Land for the Landless scheme from Gov Linden could be resold only to the Governor and for the price paid? There would be nothing to stop people buying and selling other land during this period of course, but it would safeguard First Land, and perhaps stem the tide of alts created for no other reason than to make a fast buck.
Other options:
As above but make First Land free for the first 4 weeks - a "try before you buy" arrangement. At the end of that time the resident pays 512L and the three months "no sell" clause kicks in. If the resident decides at any time during the 4 weeks that land ownership is not for her/him the land reverts to the Gov.
Limit the power of alts to acquire land. Since all paid accounts are verified it would be quite simple to ensure that premium alts cannot buy First Land. Or - a "softer" option - not for the first 3 or even 6 months of their existence. Of course some people would get round that by using someone else to create their alts, but again it would limit the number of land grabbers.