[mc32]

I think they could simplify it.

Everyone who pays for fare gets: 200lb‡ allotment (person + luggage)

If person only (no luggage) they are assumed to come under the 200lb limit, even if they don't -as this will average out with others weighing less.

People with luggage are weighed and any overage is paid for at the counter.

‡ 200 assumes that men might weigh on ave 180-ish, women 150-ish. Here's where women make back what they pay in haircuts.