At what point does that stop panning out, though? My pay is somewhat above average and management is unlikely to give me a big raise going forward without a promotion. (And at my work the next promotion would be a sort of 'team lead' position, which I'm uninterested in.)

I guess that was just a long winded way of saying: I understand where this is coming from, but in some situations the logical next step may actually be a side gig :-).