The hair on the first one does no justice to it at all. Try to be original and go for something else.
I thought of astro boy when i saw it so maybe it would have looked better if it went in that direction.
The second one needs work in the face, hair is kinda cool, but i really don't like hair on tori heads cause it's overdone.
Try to be more creative with your facial expressions.
The last one needs a lot more detail, or a lot more originality. It's just lacking and the overall design isn't good.
Look at others heads for inspiration, and try to be original and creative, never be scared to try something new.
Also as for prices, under 500 tc for all of them