What's your Spanish like?
If you're comfortable in Spanish and looking for good quality, budget accommodation, I can highly recommend Casa Naranja - https://www.facebook.com/CASA-NARANJA-M ... 436021321/
It's a couple of minutes walk up the hill from the beach and run by a very friendly family.
Or, much closer to the beach - Taroland - http://www.tarolandperu.com/
I haven't seen this place since it was done up, but met Sato, the owner when I was there a few years ago. Great guy. A local surfer. Very confident that he'll look after you.
But these are hostels, rather than hotels.
You'll probably need to get out of Mancora to get the best of the conditions in the area, though.