Me and a mate stopped at
camping la citadel in Loches, south of Tours last year.
It was a nice site, grub, cold beers, pool and nice bogs on site. Think it was 15euro for the two of us.
edit to add, the hyperlink isn't easily visible in the text, so here it is-
http://www.select-site.com/campsites...3®ionID=866