Comparison of R with proprietary software

Hi All:

Recently, I got a query how R compared cost-wise (cost of purchase, maintenance, and training manuals) with other proprietary statistical software programs (or programming environments). The request, verbatim:

<--- begin quote ---->

dear arin,

can you please find out the price of the various
prop. statistical
packages that are in general use + their per user
license fee + annual
fees etc at various scales?

this will help us to prepare a matrix as to why
people should spend
money on R or similar training ...

< --- end quote --->

I searched the web and got some quotes. I believe someone/group in this list may already have compiled a nice comparison chart with more detailed research than I can pull up with my one hour surfing. I'd greatly appreciate if anyone can share price-wise comparison between R versus popular proprietary software (SAS, SPSS, STATA, etc). 

TIA,
Arin Basu