I am comparing two types of products, a commercial product and a commercially supported opensource product and comparing the cost over a certain period.
The commercial product cost includes maintenance fees, disaster recovery site, CPU costs, cost/user. The open source product only has subscriptions fees according to CPU and users.
It is worth knowing that both of these products package-based/'off the shelf', but are two different categories of it. Maintenance fees could be referred to as OPEX costs.
What additional costs should I take into consideration to work out with more precision the cost over a time period?
e.g hardware cost for the production and disaster environments- since two products have different hardware needs as variations of application users
A very similar definition to the open source package can be found here http://cacm.acm.org/magazines/2010/8/96615-seven-principles-for-selecting-software-packages/fulltext