Mix and Match

Has any one ben able to make mix and match to work correctly. Example. Selling items $1.99 each or 3 for $5 or $.39 each or 3 for $1. RMS does not seem to be able to do this. I have allready tried the Gas Type item. IT does not work right. The main reason for mix and match is to be able to sell things for example at 3 $1.00 and .39 each, but it does not work. Any ideas beside setting item type to Gas type. RMS should fix this big limitation.