Cheap is such a subjective term. Some find what others say is expensive, is really cheap. I'm truly cheap and cheerful if that helps. More cheap than cheerful. Actually the other way round...
Many places are full then, but try those who advertise on here. Like Mathraki. Be up front, like you come across in your post. There will always be somewhere to stay in Arillas. Negotiate. Contact Olga and stay at Elena Stella with lovely pool and really simple. She runs Olga's Travel. Details available on this site.
You can do Arillas on the cheap, but spending a fortune is hard work here. It's not about that.
Send me a PM and I will share whatever I can.
Phil