2 questions about "extra" software on computers sold on ebay

[clay]

testcase wrote:
I might be wrong but, I think once 10.8 is installed on a Mac, it stays installed, even if the users are changed.

I might be wrong, too, I don't know for sure. I just recalled that a computer that I purchased that came with 10.8 installed lost it when I booted into recovery mode to wipe it clean and install a fresh copy of the OS. In that case, 10.7 was installed from the recovery partition, as it was the default OS that shipped with the machine.