SD memory question

[mgold]

So I'm getting ready to purchase a D50 and need to get SD media for it. Ramjet has an 80x 512MB card (read 12MB/sec & write 11MB/sec) for $44, or a co-worker has a 1GB standard SD card (5MB/sec read & 1.5MB/sec write) that he'll sell to me for $50. The question I have is how important is the speed of the SD card to the D50?