I have two tables in my databse

Table # 1 Item | PriceK | PriceM |Price H | Price T
This is populated with items and four prices, these prices are based on a group that the user belongs to(k,m,h, or t)
Table #2 Username | Group | Dec3 | Dec4 | Dec5 | Total
In Dec3 Dec4 etc will be an item that corresponds to the items in table#1.

I need to take the item in Dec3 and retrieve the...