How much is Manon Rhéaume's rookie card worth?

Not much, when it first came out it was right about $5.

Now you can get them for 99 cents on eBay. She never really became a big deal.

Cards back then were printed in huge quantities and the hobby moved towards really limited edition stuff. So instead of a company putting out 2–3 sets and printing millions, they put out 30 sets and print hundreds, then people pay 5 times as much because they have something “rare”.