what's the retail on this? sorry if question's been asked already

anyone ever use vatsim?

http://www.vatsim.net/

let's you link up with other sim pilots, and some play controller. -so if you
fly from DEN-LAX, you have real people vectoring you / sequencing finals, etc
the whole trip. i've perused their site but never have time to learn and
download whatever i needed - but i like i think the concept's pretty cool