I went to Wacken last year and wouldn't stay anywhere but in the camp site. Stick hotels, etc up your arse - I wouldn't swap the atmosphere of the camp site for quids.
There were 4 of us and we hired a camper van and shared the cost. I arranged it through an office here in Melbourne, picked up the van in Frankfurt and just drove straight to Hamburg. It was a bit pricey and you can only hire for a minimum of 14 days but the positives were:
- plenty of shelter when it pissed down with rain;
- slept 3 people comfortably (4th bloke drew the short straw and lobbed on the floor but it was better than a tree);
- security for your things;
- built-in shower and dunny (although we just ended up using the camp site dunnies and pissing on the hedges anyway. And we didn't give a shit about having a shower);
- kitchen for cooking your brekky;
- 15 minute walk to the main stage if you're not out in the arse-end of nowhere;
- decent CD player for playing metal loudly in a futile attempt to drown out the campsite that had massive PAs running off giant generators - awesome;
- and, best of all, a mega fridge for keeping the BYO camp-site beers at an Aussie-preferred icy cold temperature while the poor locals insisted on drinking theirs at room temperate which is a crap idea. It was worth it just for the cold piss!!!!!