I Lost £20

Yesterday, when I got home from work, I noticed that I was missing the £20 note that had been in my pocket for the last week or so. It must have fallen out sometime during the day, when I pulled my watch out. I started carrying my watch in my pocket, a couple of months ago, because the part of my watch where the strap attaches is broken, so the strap won't stay attached anymore. I can't afford to buy a new watch, so I carry my old one in my pocket, where I keep my money.
£20 is like two weeks shopping, for me. Today, at work, I asked around, but no one said he had found it. Like someone would admit to that. This is the poorest I have been in my life. A friend of mine suggested that I offer a reward for the return of the £20. What reward could I offer that is worth more than the £20 itself? She suggested that I offer an autographed picture. "Of who?" I asked.
"You," she replied.
"I don't have one to offer."
"Get one," she suggested. To get a proper 8 X 10 done and printed would cost me more than the £20.
"I don't think anyone would want my photograph more than £20, yet," I said, dejectedly.
"Like the 'yet,' " she replied. The ironic thing is, I found £20 in cash, about ten months ago, on the pavement, one day. While the universe is now somehow in balance, I really can't afford for it to be balancing on me, at the moment. I never get ahead.