Pries have gone up substantially this past year. Low-mid $30's seem to be common now and even state parks are often in the low-mid $20's. And prices around $40-50 seem to be getting common near major cities and tourist destinations. As Ned says, they are throwing in more features - full hook-up are common now, as is 50A service, wi-fi and often cable tv too. Frankly I enjoy the 50A FHU, wif and such, but the wallet is taking a beating.
I do not expect to see much ala carte pricing - the trend is the opposite. We workamp most summers and I can assure you that campers by far prefer a package price - they really grumble about extra charges, even for things they ask for. And ala cart pricing for things like CATV, wifi, 50A service, etc. is a nuisance for campgrounds to manage and collect, so they like all-in-one prices too.
Real estate costs, property & income taxes, insurance premiums and regulatory requirements are all on the rise, and steeply too, so there is no end in site.
I've been through more than a few towns where low end motel rooms are often cheaper than campgrounds.