I was having a conversation over Skype, and my friend’s mom happens to make these really cool pillow cases.  
He said that usually, they take around 2 to 3 weeks to be completed. The time gap between works is quite large, but I think it’s good for the overall quality of the final piece.
 
We were talking, and he’d like to find a way to sell them online and start taking orders, but he has no idea on how many people would be interested, or even how much they’re willing to pay.
 
So here’s what I’m asking of you, please leave a comment on how much YOU think it’s fair, for a work like this.  
Disregard the time it takes to make one, and just give a price or a constructive comment on how to approach this. :)
 
Keep in mind, that OC cutie-marks are definitely an option for a product.