actually, I heard the max is $250
and yeah, there's ports on top for GC controllers and memory cards
the back is pretty simple, 2 usb 2.0 ports, Power cord, and 1 SD memory card port
as for backwords compality, with GC, I think their disks will go into that thing by the blue light which is the place where you put the other cd's. Whoa, now that I think of it, I think Xbox 360 is the only one that kept with the cd drives that come out, the PS3's looks like you just put the cd in and so does the Wii's.
With the older games though, you will download via virtual console, games from NES, SNES, N64, Sega Genesis, and Turbo Grafx 16, therefore shooting Xbox live arcade out of the water.
http://www.gamespot.com/features/6146540/index.html