You've got pretty much zero chance of getting one for free.
Aside from the fact that would be software piracy, a recovery CD is very different from an install CD. A recovery CD restores the current installed version of Windows, and you usually get these with a computer system that is pre-loaded with Win XP (often distributed by companies such as HP)
If you paid a few $ extra when you bought your computer, you might have got a full reinstall CD - this is just an OEM copy of Windows XP. If you need to reinstall Windows and you don't have a CD or a Windows Key, you'll need to buy a new copy.
Realistically though, $80 is quite cheap for a copy of Windows.
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