I hope you don't mind me popping in! I've been doing commissions for almost two years now so I thought I could help a little but more.
Kind of going off on what Hedgemaze mentioned most people won't have a real life reference to give you along with their character. It's easier for most users to give you the character and money then leave it at that. Having to also get a real life reference may throw some of them off especially users who are new or not used to doing commissions. I would suggest changing it to 'please provide a stock photo of the pose you want' in your art thread to help minimize the confusion and help those interested in searching for some get it. I would also suggest linking some stock image websites (preferably ones that let you use them as reference without paying) so those interested can search around. The easier you make it for a client to get things together, the better!
This is one of my favorite stock sites: https://unsplash.com/collections | It's more focused on environments and stuff itself than humans but it dose have plenty of them and the photos in there are free to use! Finding more sites like that to help your clients get the stuff you need to start can help a great deal. Alternatively, you could mention the clients themselves could take photos of their preferred pose(s) provided they are comfortable sending one of themselves/a friend your way.
As for prices, I think they are fine. If the $30 mark is the min hourly wage where you live then that works. I would suggest bumping them up as you are selling a skill and shouldn't be paid minimum wage for that, but I understand when you start you sometimes have to take a hit to get out there. I would keep them at that price, then raise them later once you get a decent enough following/a few commissions under your belt. Even if it's just a dollar or two it will help in the long run. It would also good to expand to more sites than just toyhouse to help reach more people if you have not done so already. Any place where you can be constantly posting new art and getting people to both see and interact with you and your artwork will help expand your business. When you get on these new sites (if you are not on them already) it's not enough to just post your art and pop off for the day. You need to interact with the community, like/comment/talk to other people and on their art as well. Sometimes people who will love your work may pass you or miss your stuff if you don't get to them first so it's good get yourself out there as well by interacting with them too.
That's all I can think of for the moment. I hope some of this is useful to you!