It's not $20. It's 20 British pence - about 25 cents.... "Examples include some crisps, a bazinga ball, a small amount of olive oil, balsamic vinegar, or wine."
I think, reading it, it could be £1000 worth of wine. For example two cases of decent Gevrey Chambertin, I myself could bring myself to accept such a thing.
Also, who wants 10,000 <$20 items? It's a cool payout, but if I wanted to spend ~$200,000, I wouldn't do it in 10,000 pieces.