UBUNTU
you can't
it is illegal to do this
OS=Operating Systemyou are basicly saying that how much is iPhone 'operating sytem' 4 which is well free you can download the OS update free from itunes however if you was meant to say how much is iPhone 4 well I'll say iPhone 16gb between £400-£500 but it depends what shop it is
IrfanView is free software that is compatible with OS products. You can download this software for free online from websites such as Cnet and FileHippo.
Almost all the linux OS's are free you can find them at their websites .
Download Limewire's free version for your computer and you can download all music for free, it also has videos you can download etc. But the police did a sherch on this website OS be VERY VERY careful.
Windows, Unix, Mac OS
http://www.rarlab.com/download.htm Select English and OS
You could easily download Chrome for Ubuntu OS. It is available on the Chrome website as well.
Apple OS X Microsoft Windows Unix Linux VAX/VMS OS4000 IBM System/360 DOS IBM OS/2 RISK OS Free RTOS OS 2200 Exec 8 (There are lots more)
You can download free vmware images of operating systems if you search on google. For example there are two good free operating systems, first you can download ubuntu from linux or chrome os.
Legally, some apps (Google Play for instance) has free movies to download.