Upload & Sell: Off
Walmart is offering the new dell Windows 8.1 Venue 8 Pro for 225 roughly plus taxes. They are sold out online, but you can have it reserved at a store and pick it up locally if avaiable.
This has a 32 gb SSD, Micro SD slot (usable with the x64gb cards), and a micro USB port that can be used as an I/O port full size with an adapter (5-10 usd on amazon). This allows you to import just like you would on a computer, use familiar software like Irfan View, NX2, PS Elements, all on the go and view your shots in the field.
I would believe this to be the cheapest option out there that is viable. It has the Bay Trail atom processor which is more than enough for what it has thrown it at - of course it is a windows device, so it will bog up / slow up over time. Fresh installs usually fix this though. Side perk - it also includes the full student / home edition of Microsoft office. Downside - no external keyboard case designed specifically for it yet, pen input is not a wacom based like the Surface Pro and Samsung Note. . .
If you have the cash - go with a Surface Pro 2 or 1 as others have suggested. But for that price, you may as well pick up an older model macbook air and have the same portability but higher userability - lack of touch screen though obviously.