When I looked in my wallet, I only had twenties and a single.
"I'm sorry to do this to you," I admitted, "but I only have a $20."
I handed it over, and he poked around in the cash box.
"I don't have any change so just don't worry about it," he demanded.
"NO!" I answered vehemently. "I'm not taking your tomato. This is your livelihood!"
"Well," he suggested, "do you live nearby?"
I do actually.
"Just drop it off the next time you drive by."
I gave him the $1 I did have. "Okay," I compromised, "now you have some change. Monday I'm going back to the vet so I'll drop off the $1.50 I owe you."
When you live in the country, and a kindly gentleman restores (some of) your faith in humanity, $2.51 is a small price to pay.