Actually the CHEAPEST way for multiple installs is to take out a Technet subscription.
You can get MULTIPLE KEYS for each product you download from technet - people say you can get up to 10 keys for each product. I've never reached that limit yet but you can certainly get extra keys for installing your product on a number of PC's
-- BUT READ THE EULA - these products from technet aren't meant to be used in a COMMERCIAL or PRODUCTIVE environment.
Cheers
jimbo
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Custom built, several laptops HP/ASUS
OS
Linux CENTOS 7 / various Windows OS'es and servers