Anubis' IRL friend here.
We're probably looking at an average price of about $10-$15 for each one, mostly dependent on the time required, and therefore the amount of detail. It's not very apparent from the picture (the lighting is terrible ><) but the amount of detail on the penguins took well over an hour for each one. $2-3 would probably get something like a rose or paopu fruit, $5-7 would probably get a simple Pokemon like Voltorb. $10-$15 would be a standard penguin-sized charm (most figures will be in this price bracket), and $20+ would get you something ridiculously detailed like a 2-3 inch tall Groudon. (I'll see if we can get pictures posted of him; he's really cool!)
We're shying away from chibi charms due to the overwhelming amount of detail for such a small size, but if there's a high enough demand, they're entirely possible. If we do, just know that chibis will lean towards the more expensive side, and the uncommissioned selection size will likely be smallish.
Commissions would be difficult unless we manage to get a portable oven (clay needs to be baked at high temperature) that we can bring to convention, or do mail orders//delivery after con. Anubis is refraining from doing mail orders for larger figurines due to the possibility of things breaking. The best bet for commissions would probably be to place orders ahead of time and allow you to pick them up at convention. Any other ideas?
But yeah, don't quote me on all of this yet because con is still quite a ways away and Anubis wouldn't like me putting words in her mouth.
Thanks for all the feedback, everyone!