I get what you are saying about having multiple revenue streams. The prices and lack of funding is one of the reasons why I haven't made more progress on the project before now. It is tough if you feel like all the work is going towards nothing.
I like the idea of having a market for different ships and weapons....etc. I could certainly see if a large set of games became popular and it was more like a virtual arcade that the traffic generated could lead to advertising revenue / sponsorships.
I have thought about the viability of this type of funding system in relation to the SPS and the game itself. I think that if the majority of the funds end up staying in the system by paying other Steemians to help with development and marketing that can be positive and if there are tons of activities and entertainment for Steemians to stick around and participate in this economy it could make the SEO funnel bigger and bigger to where the advertising revenue of Steemit and some of the other associated websites / apps could support themselves without selling tons of STEEM. But that is a long term macro level thing.
Otherwise it can become this thing where people are always chasing the carrot but if the tide is going out too fast the funds dry up and everything turns into somewhat of a ghost town.