Excel 2007 : Using multiple Index-Match functions

Hello,

I am having some issues with a workbook I'm working on. I'm trying to quote prices on one sheet from data from another spreadsheet. The idea is to type the name of the prescription, select the dosage, and it will give you the price from the data in the 'Prices' sheet.

However, I am having two problems that I think are associated with my choice to use Index-Match. First of all, if I have more than one prescription with the same name, it does not matter what dosage I choose it will give me the same price for both.

Second, sometimes when I type a prescription in the Generic column it will give me the dosage but the price won't show up.

Can anyone help me figure out what I am missing? I have attached an example of the workbook.

Thank you!