Those are super cute! The only issues I see are the lack of detail in the mane and tail and a lack of grounding/fitting the horse into the background (there's probably a tutorial on DA somewhere and Jello has a great hair tutorial).
Overall I'd price you at 10-15k depending on complexity, but that might be my bad pricing skills kicking in, so don't quote me on it-but a general guideline and if a couple more people say about the same thing I'd do that. You can also raise prices as you start improving.
Good job!
Sunny
