Adobe has released a Creative Suite package every ~20 months (Wikipedia).
CS1 - 09/2003
CS2 - 04/2005 - 19 Months
CS3 - 03/2007 - 23 Months
CS4 - 10/2008 - 19 Months
CS5 - 04/2010 - 18 Months
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If we bought the first premium suite (based off current prices in the Adobe Store) it would have cost us around $1900. Add in upgrades at $400 each, and we get a total lifetime cost of $3500.
If subscription pricing was around since day one and we went with the new subscription pricing monthly rate of $95 (with one year contract) we would end up paying ~ $8650 to date or about 2.5x of buying it over that period (91 Months).
I don't find it surprising that they're going down this route. It surely is an interesting way to charge for downloaded software as we've really only seen this on the web front thus far.
I'm a bit interested to see how many total subscriptions we'll sign up for in a couple years. Reoccurring billing is certainly a nice stream of cash - and a bit of a trojan horse for additional revenue ;)