If I already got one 128M for spare. Then I will buy 1x512M only
No need to keep so many cards on hand
Fully utilise the memory (for 2X256M, if the DC needs 3M for a photos, when the 256M card left 2M, then we can't take any more, and wasted 4M in total. But for 512, you can take one more photo and waste 1M only.)
And pls select the CF with 3-5 years gurranttee.
such as Scandisk/Ultra II, Kingston...etc
512M is a bit expensive than 256M.
Just because more and more people use 4M/5MP DC, they all need larger capacity's memory card. Higher market demand, price is also higher.