Lookup

The setup of the spreadsheet is as follows:

Column A: Item Number, Column B: Quantity, Column C: Price

I want to create a spreadsheet to lookup values in a table as follows:

1. Enter the item and quantity into Excel and have it narrow the results of
the table based on my inputs.

2. Have Excel give me an average price based corresponding to the item
number and quantity I entered.

The part I can’t figure out is how to have Excel filter results. I don’t
want Excel to report an average price of all the values corresponding to the
item number and quantity it looked up, rather to report an average price
within a certain range. For example, if I say lookup item number 1001 at a
quantity of 100 Each, I want it to give me an average price of item 1001 in
the table within a range of 50 – 150 Each and exclude the rest of the results
it found.

How can I setup my spreadsheet to:

1. Enter and Item Number and Quantity and have it filter the results I enter.
2. Report an average price based on the criteria I mentioned above.