Sometimes I get the strong impression that the proposal creation process in Area 51 is mostly broken.
New Users almost always create new proposals rather than search for and commit to similar existing proposals.
For this reason I believe that Area 51 should raise the requirement for creating a proposal to between 400-500 rep points.
IMHO many of the users that have 300 or less reputation typically are unaware of Area 51's systemic duplicate proposal issues. By forcing new users to gain a little reputation first, they have to spend some time thinking about supporting similar proposals rather than rashly creating their own.
Furthermore, Area 51 doesn't need more proposals, it needs less. (At this point in time)
Unlike other sites that typically benefit from more questions and answers, Area 51 does not necessarily benefit from more proposals. This is because proposals that overlap with other proposals suck the energy out of each other and confuse both old and new users.
Creating new proposal ideas is not very difficult for anyone, better that more experienced users be the ones behind this process.