The demands of money-counting skills potentially limit individuals with intellectual disability (ID) to master the one-more-than technique, particularly in Taiwan, which requires high daily minimum living expense for supporting an individual's daily life. Employing a multiple treatment design across price ranges and settings, this study compared effects of two approaches of the one-more-than technique on the independent payment for four male secondary school students with moderate ID. Results demonstrated that the approach using the mobile purchasing assistance system (MPAS approach), embedded with the one-more-than technique, was of greater benefit than simply using the traditional one-more-than technique (TOMT approach) to instruct students with inconsistency of money-counting skills to independently purchase goods costing high a level of price range, reaching the daily minimum living expense in local environment. Furthermore, the newly acquired skill was effectively maintained and generalized to four non-trained new environments for at least eight weeks after the removal of the MPAS intervention.