Cost of Ownership:
How much does cost to use Perforce? That depends on how much time you current use with version control.
If used it 100%, which is impossible it would cost 36 cents/hour the first year and only 8 cents/hour after that.

Where to get it:

http://www.perforce.com/perforce/loadprog.html is the link to download the server and clients. You don't pay anything to start using Perforce. When you start using it with more then 2 people, you will have to get an evaluation license from Perforce.
wget http://perforce.com/perforce/doc.081/manuals/cmdref/cmdref.pdf
Mac Notes: http://kb.perforce.com/HardwareOsNe..rkReference/OperatingSystems/Mac/Pe...

Perforce links:
http://public.perforce.com/wiki/Perforce_MediaWiki_extension#p4graph
http://public.perforce.com:8080/@rev1=head@//public/perforce/faq/build.html
http://www.ravenbrook.com/project/p4dti/master/test/
http://www.ravenbrook.com/project/p4dti/

Mac Links:
P4 Cocoa GUI
Using launchd to start P4 on Mac 10.4+

Perforce Defect Integration
http://www.ravenbrook.com/doc/2003/02/24/requirements-and-change/

Mantis Integration:
http://www.mantisbt.org/bugs/view.php?id=3758

TFS comparison link:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=543517&SiteID=1

http://chanson.livejournal.com/2004/02/15/ Click on recent entries, he says things about SVN and Apple.

Negative Links:
http://weblog.masukomi.org/2007/8/31/dear-perforce-fuck-you
http://reddit.com/r/programming/info/2n4qo/comments/