That was an awesome answer. Sometimes constraints clear our thinking, other times we can focus on them to our detriment.
It's a great point that $5 is worth basically nothing in this scenario, but it would be interesting to know at what point $N becomes worth something potentially greater than $N in this fixed amount of time.
Nice how every solution (except the bike-pump) business, involved abusing someone's trust or creating negative externalities (artificially extending lines, hijacking class time).