If you plan to spent your holidays in Sri Lanka and looking for a reasonable price. I can recommend you to rent a Guest House instead of a hotel. Sri Lanka is really safe place for wild travelers. It's the safest place in Asia, where you can enjoy your holidays. Of course it's difficult to find a good guesthouse in Sri Lanka, but when you find it you save a lot of money. The price for the hotel is vary from 50$ to 100$ per night. The price for Guest house is vary from 6$ to 25$. And don't worry, you will get a clean room, with fan or AC depending on price and a fresh brekfast on the beach with a great ocean view.
You can see the example photos of lankian Guest Houses. In most cases it's quite clean and nice houses, with 2 or 3 stores. With a verando downstairs or a smal restaraount on the beach.