Because this is the original colorway of the Nike Cortez i think they will never be hard to come by. Nike will always produce this shoe in this colourway again and again and again...
Here are some options to buy this shoe after clicking on the first 5 googlesearch links.
Leather version at a bargain price:
http://hhsneakercity.com/Nike-Cortez-Ba ... r-Red-4183
Quickstrike OG version (with the original heel section, bigger swooth and slightly different logos, but only for mr bigfoot):
http://www.thegoodwillout.com/product_i ... info=p2680
Of course you can always use Nike ID to colour the shoe yourself, choose the upper materials and print your name or the name of Forrest Gump on the heels. Price: 115$
http://store.nike.com/us/en_us/product/ ... id=2066991
Hope this helps.