The coin is probably good value as a longterm investing if the NZ did win it. But it is a gamble, and you would be hoping for an NZ win. You could always buy after the win, but perhaps they would then have sold out.
Limited market IMHO as with most collectables. Unless you find something genuinely collectable with an inherent value (such as historic gold [gold coins, sovereigns etc] which has an intrinsic bullion value) then its not so much an investment as it is a hobby. I collect both stamps and coins from specialised areas (DDR and Third Reich) which have appreciated in value. If you are look at collecting something that may appreciate in value then take advantage of the high dollar and look at highly desirable stamps and coins and for investment purposes try to predict what will be popular. just got the following for a good price for instance (used)
1933 Air. ?Graf Zeppelin? Chicago World Exhibition Flight. Optd Chicagofahrt Weltausstellung 1933.
Unused Used Stock 1m. red ?600.00 ?325.00 2m. blue ?65.00 ?160.00 4m. brown ?65.00 ?160.00