I'm confused here. People who hoard their sP for the shop till and richest user achievements won't be driving prices up in user shops because they won't be spending it. Well, they might go on a spending spree once they've got their rewards but it still depends on what they buy. There are a lot of ways to spend sP which doesn't involve user shops such as the Millionaire Center, Skitters Shop, the Brewery during Alegarten, the Potion Lottery etc etc
The only thing that's really been inflated is the cost of CSC gift cards in user shops. New restockables are always ridiculously inflated at first but they invariably come down in price after a while. In the past week or so I bought the Brown Graceful Witch Gown to complete the set, the last two brooms I needed for the Flighty Witch Broom (Take Flight Achievement prize) and a Blackheart Hollow book. They all came out of my shop till takings because people have bought a lot of quest items from me.
You know what would get people playing games without having to deal with extra items or more currencies?
A chance for intelligence. Not even points for every game, even, just the chance for it. Stick a "you might get a 1/20 chance for an intelligence point for playing this game" or heck, even a "1/50 chance" and you'd have a whole slew of people voluntarily playing games every day.
I might play a few games for a 1/20 chance but not for a 1/50. We can only send in 10 scores a day for most games and few people are good at every game so it could take days for that chance to materialise. I'd rather spend my time on here doing quests and restocking to earn sP to buy books.
I like the idea of being able to buy achievement prizes with "game points" or whatever. I need a bunch of plushies and stuff from them but even if I practiced all day everyday I'm not going to get good at, say, Spectrail. It's not going to happen. But I'd play Caliph's Tomb and Dark Matter Dice and a couple other things to save up for them, for sure.
Just supporting the chance for intelligence idea. I mean, you can already purchase intelligence now by playing Mystic Spindles, but as the pet's intelligence stat goes up, so does the number of intelligence points you have to grind from that game in order to raise that stat by one - and it quickly/eventually (depending on your boredom threshold) becomes a slog to grind. So I wouldn't mind the chance to earn intelligence by playing other games as well.