Hi AFG
Have a look on any software manufactures websites, and you will find both upgrades and full versions. (The upgrades are cheaper as if you already have a previous version many of the features are already in it)
This has been common practice since the at least 60s, (Or possibly even earlier) although it only became mainstream in the 80s.
Regards

Bill
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English Riviera:
Live entertainment, Real Ale, Great Scenery, Great Beaches, why would anyone want to live anywhere else (I�m definitely staying put).