A recent survey conducted by the Society for Human Resource Management found that a number of companies allow their workers to buy and sell vacation time. According to the survey, 9 percent of employers let workers cash out unused time, 5 percent let employees purchase additional vacation days, and seven percent let employees donate vacation time to a general pool to be used by co-workers. Usually for a price of one week?s salary prorated over the course of the year, employees can buy extra time or sell and earn some extra cash. The approach is especially popular among employers that have a paid time off policy because it encourages employees to schedule their leave time.
See "Want more time off? Some employers let workers buy extra vacation days", New York Daily News, June 9, 2013