Just to further address the situation in Estes Park itself, and it's campgrounds, for me at least, the best value in camping AT COMMERCIAL CAMPGROUNDS in Estes Park is the Estes Park Campground at Mary's Lake. It's formerly a privately owned campground, now owned by Larimer County, and has always been clean and reasonable in prices. The bath houses are ALWAYS clean, though they do have pay showers ($2 in quarters for 6 minutes), which are also always clean. The sites are priced at $37/night for either full hookups or water/electric hookups. The sites are different for each, the FHU being more of the row type pull through sites, and the W/E being mostly back in sites. There is no cable here, but there is good WIFI and Verizon is excellent here as well. The sites are mostly level, though they are dirt/gravel, and there is a nice pool there as well.
Seeing as how most of the other campgrounds are usually $20 more/night more, this is a value in Estes Park. Of course, there are the campgrounds in RMNP and they are even cheaper, but they are also harder to get reservations, and walk ins can be difficult as well. Mary's Lake, while usually full on weekends, has had sites available without reservations during the week.
Like Lauren, I have no vested interest in recommending a campground, the Mary's Lake Campground! It is simply the best value in an area where value is not a proven commodity in some of the other camping venues.