This is a simple xls to web form, if you are interested in the xls please send a PM.
It only needs 1 input field per product but has a simple math equation for each.
Product 1 has 25 items per box, the user inputs the required box ammount  then is multiplied by the 25 items per box giving a total of 75.
Let me know if you have any questions.
30 freelancers are bidding on average $51 for this job
Expert in doing this sort of stuff... No upfront needed, all payments through Milestone Payment (Escrow).. Online 16 Hours a day, Can start right away.. Thanks