Nested Ifs with vLookup calculator

Need some help. I am building a calculator in which the final calculations will require multiple (nested) if arguments as well as a v Lookup I believe. Any help appreciated.

(see attached) I hope this makes sense. This calculator will help price 10000 psi, 20000 psi and 40000 psi used pumps. I have all of the data on a tab "source data". each pump is built at a certain pressure. i.e. 10000 psi, 20000 psi, or 40000 psi. These are the only three possibilities for this calculator. I need to calculate the price increase or the price decrease based on the price as built. if built as a 10000 psi, I need to get price increase for 20000 psi and 40000 psi. if built as 20000 psi, I need to get the price decrease for 10000 and the price increase for 40000 psi. these multipliers are in a table under source data tab. I can make everything work except B13, C13, and D13

I get close, but can't seem to sting my ifs correctly

any help appreciated. Thanks!

You need each piece of information, Series, Conversion From and Conversion To in separate cells, this applies to the calculator and the source data.

Then you can easily match the criteria in the calculator to the source data with a single SUMIFS function, no nested ifs or vlookups needed.