Since there's always an excess of silvers in the game and it's good for the game to have them be useful...how about having a week-long "event" where enhancives can again be permified? Put the price high enough that it makes sense to do it from management's perspective. It might not directly translate to income for Simu (which is important too), but it does keep the environment healthy.

This could be, of course, combined with lots of other things, but my personal interest happens to be in permifying things. Perhaps, for a silver cost, spell enhancives could be recharged? (I don't personally care about that, but it'd be a nice, easy, way to suck up silvers.