Sketches: 100k - 500k, depending on the size and difficulty

Pixel Dolls: 300k for the first two (for one ^^) - Second example up to 800k, depending on difficulty again. The one in your Forumset including background around 600k.

Pixel Sketch: If you finish this one I'm sure it could go for ~800k ^^ Bigger ones maybe more.

These are only what I would pay for them btw xD I like your pixel dolls, they are very cute ^^