Sumproduct with multiple criteria and ignoring text values

Hello all, I've looked through a number of posts but am still having an issue.

Using Excel 2010, I am trying to do a Sumproduct formula with two criteria, one of which needs to ignore text values. Here is the set up:

Column A Column B Column C
(Side) (Qty) (Price)
Buy 5,512 15.67
Sell 119,428 null
Buy 24,209 45.77
Sell 20,054 12.25
...

I'm trying to find the sumproduct of Qty * Price if the side equals "Buy" (or "Sell") but ignoring the "null" value in column C. The formula I have is =SUMPRODUCT(--($A$2:$A$20="Buy")*IF(ISNUMBER($C$2:$C$20),--($B$2:$B$20*$C$2:$C$20)))

The result in the cell is 0, but if I open the Insert Function dialog box, I see the correct value being returned. Does anyone know why this may be, or have a different way of going about this?

Thanks for the help!

Try

=SUMPRODUCT(--($A$2:$A$20="Buy"),$B$2:$B$20,$C$2:$C$20)

Thanks Jonmo and Tony for the quick responses! I had more luck with Jonmo's, but I'll play around with the Match formula to see if I can get it another way.

Much appreciated!

Originally Posted by soapy

Thanks Jonmo and Tony for the quick responses

You're welcome.

Originally Posted by soapy

Price if the side equals "Buy" (or "Sell")

That was a bit confusing the way you wrote that.
I think Tony interpraited that to mean you wanted to count both Buy and Sell in a single formula
But I think you meant you intended to have 2 seperate formulas, one for Buy and one for Sell