wow, you save 2.10 with that coupon, for sure not the best deal, its alot cheaper with www.dealextreme.com but shipping takes awhile (its free so its fine with me)
As for the R4, its a great card, but showing age and unsure if the R4 team is gonna release any new updates for it. It doesn't have SDHC support also, another negetive for the card. But you can buy 2 kingston 2GB Japans cheaper than 1 4GB SDHC card (probably lossing more space with 4gb than a 2gb also after format)