16GB Transcend Class 10 SDHC 300x for $7 {or 16GB 200x for $6 each}

If you like 16GB memory cards and you are fine with lower speeds, the 16GB Transcend Class 10 SDHC, 300x (up to 45MB/sec read), model TS16GSDU1 or TS16GSDU1E (frustration free packaging) is on sale for $7 per card at Amazon by Amazon herself. The limit is five per customer, but since they have them on sale in both the frustration free packaging and the standard packaging, you may be able to get five of each for a total of ten (I haven’t tried this).

If you like 16GB memory cards and you are fine with even lower speed, the 16GB Transcend Class 10 SDHC, 200x (up to 30MB/sec read), model TS16GSDHC10 or TS16GSDHC10E (frustration free packaging) is on sale for $6 per card at Amazon by Amazon herself. The limit is five per customer, but since they have them on sale in both the frustration free packaging and the standard packaging, you may be able to get five of each for a total of ten (I haven’t tried this).

Prime membership gets you free 2-day shipping even if you buy only one card (they are not part of the dreaded Add-On program). Non-Prime members get the usual $35+ free super-shaver-shipping.