Recently a question came up on Oracle-L, but to tell you the truth it might have been anywhere about how on earth  one justified Oracle's licensing.  The question was

To get an idea of how much it would cost to license a point of sale database on Oracle and commodity hardware/software, we requested a quote for a 2-node RAC on Dell 2950's 2 Dual core's per server.  Quote was $306k.

Well if I were the business I'd choke as well. That's an indefensible software cost for that sort of install. I costed up a quad-core E5430 version of the above hardware, complete with, RHEL5, 16gb RAM and redundant SAN connections. Total cost of the hardware (but excluding the SAN/NFS storage that you'd use for RAC) just about $20,000. That's for the two servers. So the questioner was being quoted 15x the cost of the hardware (and 3 years worth or so of DBA time at US rates last time I looked) for the Oracle software. Any time you see the software costing more than dedicated admins and an order of magnitude higher than the hardware/OS then you have to work very hard to justify the cost.

There is an alternative though Oracle Standard Edition will do all of the above for you on that hardware. The Oracle store quote for the dual quad-core machines I listed above was $65k Now that's a much more defensible - though still high cost. Now it may be that the EE only features (DataGuard, Flashback Table (not query), block level recovery, the pl/sql function result cache in 11 and so on) are worth nearly $250k for the questioners business, but you do have to wonder. Of course on my quad-core based install the EE license fee would be $468,000

Update following Herod's comment and to make my quote clear. This is the oracle store quote for 8 processor licenses for both EE and RAC based on 50% of the total number of cores in the system. Next to it is the US pricing for the hardware