I know you have performance issues with the amount of prims in a region. However, as a basic account player I can't see paying $10 a month for 512 sq. m. and 117 prims. I've looked at some of these lots and they are about like living as a homeless person in a small back alley out of a cardboard box. It's about worth $5 a month at the very most. Perhaps you should consider adjusting your rates so the initial 512 sq. m. lots start at $5 a month and the 1024 sq. m. lots at $10 a month and raise the prim limits on each. It's no wonder so many players never upgrade from free accounts with the way this is choked down right now. Especially for those who aren't interested in much more than having a home without having to be on a hamster wheel to keep up with the payments on renting.
After a discussion with one forum reader online in SL, I should qualify that I don't consider the first 512 sq. m. with 117 prims free like the chart shows. It requires the $10 premium account fee after all and there's not much reason to have a premium account if your not going to own land. So that land cost chart is really $10, $15, $18, and etc.
The casual players aren't going to upgrade from free the way this is now. Your ring in the nose tactic with this sort of can't build nothing worth spit until you upgrade and pay even more only pulls in those with alot of free time and the artistic ability to build and run businesses. Give us a decent initial tier that we can live at permanently and we might.