Shipping based on column value
I have a store that only ships priority mail. The price is determined by which flat rate box is used. Each product table has a database field called shipping and in it I put the price of the box used. I want to use the shipping column in the product table to base my shipping on.
Item 1000 uses the small flat rate box which is $5.80
Item 1001 uses the medium flat rate box which is $12.35
My patron buys 2 Item 1000s and 1 Item 1001 so the total shipping should be $23.95
I also want to set the max shipping price to $50 so no matter now many they buy they never pay over $50 total
How would I set up this rule?