Discussed in stackoverflow question.
TFS 2010 basic.. same cost as VSS
Perforce - google use it? USD$800 per user
SourceGear Vault and Fortress - good VSS upscale... USD$300 / $600
SVN.. free...VisualSVN Server.. SVN 1.6.6
fi.github.com - USD$600 per user.. min 10
cobebasehq - ??
The Big Picture
On ‘Joels Test’ here are some of my favourites:
1. Do you use source control?
4. Do you have a bug database?
6. Do you have an up-to-date schedule?
7. Do you have a spec?
8. Do programmers have quiet working conditions?
9. Do you use the best tools money can buy?
source control eg Git
bug tracking eg FogBugz
work items
continuous integration eg Cruise Control
collaberation
document management