question about 10$ and 30$ tiers rewards (Patreon)

recently I was able to reach pace to deliver updates almost on a monthly basis. This affected productivity well in general, but 'access to development area' tier 10$ reward is now almost useless, because I make content during the month and assemble it into code & story during last week before release.

So I'm asking both you and myself - what are you interested in as well? What extra could be placed on 10$ and 30$ tiers? (Casey clothes is now in development, just for reference)

off-topic: As I've said recently - improving game quality (story & art) is my biggest goal now, so I try to spend at list a full day per week working over sketches, that are not directly related to the game. You all know that I never was a professional artits, so I work over different shapes, poses, faces, etc... 

Regarding this sketch: Did Casey played volleyball at college? Probably :D

Added SFW version at attachment