Automatic Tabulation

I have created a price sheet with optional equipment listed in consecutive rows. One of the common columns in those rows is where you can input the quantity. Currently I have it set to tabulate the total price at the bottom based on the quantity. The formula I used is pretty extensive and I was wondering if there was an easier and much shorter formula that will do the same job.

I have attached the sheet. Columns E, F, G, & H are the ones that I need to automatically tabulate at the bottom according to the quantity input in column D.

Thanks in advance for the help!

Works great! Thank you, thank you!!