No not really but it seems you are missing the point. Any and All versions of Windows can only be installed on one computer at a time for each License key you have. If you have one license key that means it can only be installed on one computer. To install it on more then one you need to BUY more License Keys. Yes each new key will cost you more money.
You can buy Multiple keys from certain places at one time sometimes at a reduced price but they will still cost you more money. So if one key for Win 7 Home Premium costs $100 a Multi Pack of 3 may only cost you $275 (+/-), instead of the full $300 they would cost buying them individually. But in the end each key has a Price tag.
Personally If I was doing what you are doing, taking older system, Fixing them and then selling them, I would install the Original OS that came on the system using the original License key for that OS that is printed on the Certificate Of Authenticity sticker. Then let the new owner decide whether to upgrade it to Win 7.