Yea, what jhubbard just said basically sums it all up. The Guitar Port comes with the Port itself, a USB cable to connect it to your PC, and a audio cable, that way you can connect your guitar Port thru your sound card, and itll play out of your PC speakers. It also has 2 RCA ports on the back of the Guitar Port. This way you can connect to an external stereo/amp (if your amp has RCA's), and the software needed to run the port. Its really easy to use/navigate. Theres a ton of amp/cab models to choose from, and you can even download more if you want (but, of course, it cost money). Here's a list of the amp models that are in the software.
Line 6 Chemical X
Line 6 Insane
Line 6 Piezacoustic 2
Line 6 Spinal Puppet
1953 Small Tweed (based on "wide panel" Fender Deluxe)
1958 Tweed B-Man (based on Fender Bassman)
1964 Blackface 'Lux (based on Fender Deluxe Reverb)
1967 Class A-30 Top Boost (based on Vox AC-30)
1968 Plexi Lead (based on Marshall Super Lead)
1968 Plexi Jump Lead (based on Marshall Super Lead with "jumped" channels)
1987 Jazz Clean (based on Roland JC-120)
1990 Brit J-800 (based on Marshall JCM-800)
1993 Solo 100 Head (based on Soldano SLO-100)
2001 Treadplate (based on Mesa Boogie Dual Rectifier)
Tube Instrument Preamp
The best part about the Port (in my opinion) is that it has a big black volume knob right ontop of the Port.
Hope that clears everything up. Oh, also. I dont know EXACTLY how much it costs, because I got it for X-Mas. I think its like, $100usd or something.