How about DX50 with 640GB via USB OTG?
We've been talking about how to get some micro-to-mini OTG cables with right-angled connectors on both ends
http://www.head-fi.org/t/691503/micro-usb-male-to-mini-usb-male
Then grab this 2.5" SATA to mini USB enclosure for 10 bucks
http://www.amazon.com/MANHATTAN-Hi-Speed-2-5-Inch-Enclosure-130103/dp/B002RMB5C6
Finally import Thanko 55KBDSSD from Japan for 50 bucks for so
http://www.amazon.co.jp/dp/B00GXREJ92
Prices of micro SDXC cards are still dropping so it's gonna be awesome to get 10 of them for cheap.