And for that 15 dollars I have played over 1300 hours or little over a penny an hour for entertainment.
Games tend to go on sale after being out long enough to show dramatically decreasing sales, while the development team has moved on. This one's still doing well, and is in the process of a significant update--so that will be unlikely before the end of the holiday season. If you can hold out, I'd suggest waiting until at least then. There's no guarantee, but that should be your first clear shot at a sale. Best of luck.