Gameloft is running a sale for the in game gem currency, dropping them down to half price. There isn't a specific timetable for how long it will last, but I'm guessing it has something to do with Black Friday.
Along with that, Rainbow Dash has been lowered to 90 gems. She's still worth more than buying a real life vinyl version, but the hardcore players out there might finally be able to complete the game now that she doesn't cost as much as two brand new xbox games!
Check out their facebook for updates.
Thanks to Phillip for the heads up.