I don't know about Xplor for sure, but Xcaret and Xel-Ha both charge somewhere close to half price for locals. Since Xplor is part of the same company, I'd assume it's also around half the regular price.
I asked them on Twitter, and Xplor tells me it's $650 pesos, half the regular price. It includes most of the activities (zip line, rafts, amphibeous vehicles, etc etc), unlimited juices and natural drinks, your equipment, showers, locker, parking and buffet.
there is a promocion right now with $2000 for a YEAR at Xcaret and that includes 1 xplor. I'd jump all over that.
