In reply to adventure_vulture: Have a look at this article
http://m.guardian.co.uk/travel/2009/dec/05/camping-on-gran-canaria .
I've made vague enquiries into camping in GC before, but never done anything - the appeal and ease of staying at my other half's parent's house has been to strong.
A few of things though. The campsites and picnic areas around the summit can be very busy with locals of winter and spring weekends (in the summer apparently the mountains get too warm and they all head to the north coast instead).
Don't be fooled by the size of the island; away from the south and east coast it can take ages to get around, and the higher areas (where most of the campsites are) especially around Tamadaba can feel fairly remote.
Away from the major tourist hotspots (Playa de la Ingles, Puerto de Mogan, Puerto Rico etc.), especially in the north of the island you may well be able to find some reasonably priced apartments - areas that attract more Canarians than Skandies or Germans are a lot lower cost.
Not trying to put you off (it is an amazing island), and it depends upon what you want to do with your time there, but camping may be a little more faffy than it would be in the UK or somewhere like France.