Cost of Surgery to Produce Monolids for the Eyes?

No known surgical techniques exists for the issue your are concerned about. I am concerned of your realistic expectations in requesting this type of surgery. Maybe you should seek additional in person evaluations. 

You raise an interesting request. For the longest time, surgical techniques for doing the reverse have been taught. To the best of my knowledge, I am not aware of any surgical procedures. I could theoretically device one by detaching the fibers that create the upper eyelid crease but it remains theoretical and I would not advise it. I look forward to other surgeon's responses in this regard.