I will not mix and match. The tapes are placed in plastic slipcases with printed spine labels. Only send in 1 request. When you get your tapes, then and only then can you order again. There is no limit to the amount of tapes you order in a single request.
Prices go by the chart.
But tape requests exceeding 3 tapes will have to be in cash or money order. All tapes are copied in SP mode. T-160's are longer, not better quality. I use BASF SHG's T-160. All these prices include shipping and handling.