$15 for a basic repaint of one of the minis I have. This includes painting on any details of your character and any cutting into the figure. For example, $15 would include cutting off a horn to make an earth pony, cutting into a wing or ear to simulate an injury or scar, etc.
$25 to cut off the hair on the model and sculpt a new mane and tail to match your OC. For an extra $5 I can also sculpt some minor accessories such as necklaces, simple clothes, etc, or turn a mare figure into a stallion.