I think you are more likely to find women who go topless b/c they want to as opposed to the women who do the scale pricing thing. There are some women who will do topless, or nude, or........ for "X" amount more. On the other hand there have been times when a lady has said she will do topless for a little bit more. I go to see her, and don't pay for topless, then she ends up taking her top up. When I saw "Scar" a few months ago, I did not pay for topless and she held to that. Topless is usually my minimum requirement unless she says up front what her rules are. In the end it is a matter of comfort for the women
But to answer your question, a couple of women I think will do topless are (and put a "?" behind all of these names):
Colette G.
Jana
Christine M.
Debra D.
Storm (UK)
Justine Delts
Trapalicious
Clarkflex