This Khao Sarn zone hotel is enthusiastically recommended for people who don't care about getting a good night's sleep, and enjoy spending the night tossing and turning in bed covered in sweat. The 'hotel' has the annoying habit of many Thai budget places of installing air-con, but then turning it down so low that you can hardly tell the thing is turned on. You are better advised to stay in a fan room in one of the grotty doss-houses nearby. At least you'll get a better night's sleep that way, if you can put up with the smell.
Yes, there are river views from the more expensive rooms, but the traveller who wants a river view in Khao Sarn zone is recommended to go stay in the Navalai hotel instead, which offers a better bet in every way.
The above rates are net per room per night and inclusive of service charge and breakfast for 2 people.