Sold a $7 Secrets book!

I sold a $7 secrets book! Yippee! I paid $7 USD for it and now have my $7 back minus the paypal fees. ($0.50) If I sell one more then it was a good buy. I still haven't taken the time to apply the technique to my spreadsheet. It is on my list of things to do. The problem is that the money is in paypal in US dollars. Since my blog is in Canadian dollars, the Canadian value is going to change day to day until I withdraw the money, so how do I represent this? I think I'll have to just put a US dollar section on the side until I withdraw the money. Remember, this sells with resale rights, so if you buy it off me then you only have to sell one to get your money back (minus paypal fees)