The $20 quote is for two chairs and one umbrella. Each chair is $7 and an umbrella is $6. You can get as many or as few of each as you like. Just find a spot that you like that is not on the first row and sit down. A beach boy will come by and take your money and provide umbrellas if none are by the chairs you want. You can bring your own drinks and eats of buy some at The Perch or Papagayo.