Design or edit a woocemmerce Wordpress pricing plugin to enable my bespoke BOGO50% off deal

Design or edit a woocemmerce Wordpress pricing plugin to enable my bespoke BOGO50% off deal. I have currently downloaded the relevant pricing plugins available and although comprehensive they need editing to allow my BOGO50%off deal.. offer as follows: "Buy category" Has different priced selected items "Get category" Includes every item in the shop.. including the "Buy Category" Select a "Buy item" with any item in the store including a second "Buy item" and the lowest priced item will be 50% off. This offer can be duplicated unlimited amounts of times continually discounting the lowest priced items in the basket. The deal is to ONLY work if the item in the "BUY CATEGORY" has been selected. This deal is not simple as people have offered already and i have had to cancel as they haven't a clue. Please read this fully and only reply if you fully understand.. if you are accepting this as a project please write the word BLUE at the top of your message so i know you fully understand. Thanks :)