IF AND Formula HELP

Hi All!

I am trying to create something totally out with my capabilities so hope you can help...…

I have created a table from which I have created a list, when I choose these items from a list I want them to add different data to different cells...

For Example...

=IF(A6="PL202 Type W","0.5","0") but I want "0.5" to be multiplied by B6 which is a number AND only IF B6 >0 (this is the easy part hopefully)

I also want

=IF(A6="PL202 Type W","14","0") but I also want different permutations too such as =IF(A6="PL202 Type X","6","0") but I want them to all add together in one cell as there may be 20 different options from 20 different cells.

Really hope you can help.

Thanks in advance