Serious Question Del Dia

The other day I found a ten-dollar bill in the pocket of my jeans. By the way I acted, you would’ve thought I’d found a love letter from Lance Kerwin or an autographed photograph of the Loch Ness Monster. I think I spent it all on a pack of Razzles and a Whizzer.
I’m doing research for a top-secret project, and need (yes, NEED … not just WANT) to know: How much money does it take for you to get happy when you come across it unexpectedly in your pocket? Please tell me in comments, below. And know this: Every comment is as thrilling to me as an unexpected ten-dollar bill (or kiss from the dreamy star of James At 15 [or 16] or glimpse of Nessie).