B&H Photo-Video offers the SanDisk Extreme PRO 64GB CompactFlash Memory Card, model no. SDCFXPS-064G-A46, for $149.95 with free shipping. (Amazon and Adorama charge the same.) That's the lowest total price we could find by $29. It features read speeds of up to 160MB/s and write speeds of up to 150MB/s.