I can be commissioned to paint doll heads for $45 - all sizes. Eyelashes are an additional $3 unless the user provides their own. I would highly prefer that the doll be sent clean and without faceup. To remove any prior faceup or to clean the head it'll be an additional $10.
I use Zoukeimura paint and pastels, Mugyo Gallery soft pastels, MSC, thinner, etc.
My turnaround time is around 2 weeks to 1 month depending on the weather and life in general.
Please note that if there's an example you like out of my previous works I can paint it similar and with the same feeling / atmosphere but I can't copy it.
Last thing to note: My work is not perfect. Lines won't be perfectly symmetrical and the work will look organic as everything is painted by hand. This is just a hobby I enjoy and not something I do professionally. But that being said, I will try to make your doll as beautiful and as perfect as I can get it to be. :)