from my reading of the post, that's not a bad price considering he'd 1st have to remove ALL the skim coat,,, we would never apply our products of another's surface,,, look at it this way - if some's already come up, what's to prevent more from delaminating AFTER any repairs're done,,, who would YOU call then ? ? ?
i'm betting it ( skim coat ) is/was either a splatter texture OR ' cool deck ' mtl that the owner got done by the cheapest bidder,,, you're never sorry you bought the best ! ! ! any const supply house'll have polymer-modified cementitious materials that would be suitable IF you know what qualities you need,,, as w/any repair, prep's the most important part of the job,,, concrete resurfacing's more a mix of skill & knowledge than anything else,,, that's why its a specialty trade,,, btw, there's nothing in an apron store that's suitable despite what the apron-wearer says.