The cave house in Finikia is a wonderful value if you don't need a view! You are literally less than a 10 minute walk from Oia for a fraction of the cost! The house is very clean and comfortable. You have to remember that this is a cave house so there aren't really any windows and so it can feel a little musty in the bathroom, but it's the nature of the beastg.
You can't drive through Oia or Finikia so the fact that this place is located right at the beginning of the town is very nice because you don't have to meander through too many walkways before getting to the main road. Lefteris was so nice to wait for us as our flight was late and I kept getting lost trying to find the parking lot we were supposed to meet. Next time I'll remember just to turn at the Santorinin Mu restaurant before I hit Oia. If you pass the rental car place you've gone too far. He also had a bottle of wine and fresh fruit for us when we got there! He was always very quick to respond to any of our questions!