you should charge 10-15 cents based on overall condition. you should clean the floor very well, then get some snapback (johnsons product ) mixed 1 part snapback to 2 parts water and spraybuff the floor using a uhs buffer. if the floor is a bit roughed up i would probably go ahead and use a combo pad or a hoghair pad. go in forward and reverse motion. on the foward pass spray the sprabuuf directly infront of the buffer making sure not to over wet the pad on the reverse pass go slow and it should come out great.