Surge Guard model 34730 for sale - $135
The 34730 is a portable surge suppressor and power monitor. It provides surge protection and over/under voltage protection. The LCD readout shows voltage and current draw. This is a 30 amp unit and plugs into the campground pedestal, then your camper plugs into it. It is brand new, never been used. I bought it and never got to use it before getting a 50 amp camper.
Here's the spec sheet: http://www.trci.net/products/surge-guard-rv/hardwires-portables/30a-portable-wlcd-display
New ones are currently priced around $263 - http://www.amazon.com/Surge-Guard-30amp-Portable-Display/dp/B008EUEOY6/ref=sr_1_4?ie=UTF8&qid=1418264120&sr=8-4&keywords=surge+guard+surge+protector