All purchased skins will be lost when you reload the plugin or reboot the server!
There is a serious problem.Fixed
The skin purchases are saved to the data/SkinShop/ directory so will be reloaded to the players when you restart.
Note data save occurs on server save (so if you hard rebooted the server without taking it off properly then you could lose some data between the last server save)...but this applies to pretty much all plugins. Server saves happen ever couple of minutes or so.
Merged post
Sorry confirmed this is actually an issue in the latest version and will be fixed shortly.
Merged post
This should be working correctly now in version 0.2.2
Locked automatically