Behodar: There is no 5 computer limitation but it's only for systems that you own. If you sell the system then the licence would no longer be valid.
(i) to download, install, use and run for personal, non-commercial use, one (1) copy of the Apple Software directly on each Apple-branded computer running OS X Lion or OS X Snow Leopard ("Mac Computer") that you own or control;
That's what I thought. So technically I should only sell it with Lion, as that is what it had when purchased? (which is quite academic because I don't have Lion media and therefore can't install it).