Why not creating demand for the currency through hard to get rewards that can be purchased for coins, and where the rewards have some kind of connection to the science projects being conducted? I am thinking of something like a 1 on 1 meeting with a noble price winner or famous researcher. Naming of celestial object etc. The money paid for the price could easily go back to a fund that supports the development of BOINC or GRC. Just some thoughts from my side