Seems like a 5 people office that like to use BlackPearl will face the issue of a expensive cost of Implementation.
Even using a Windows Server 2012 Foundation
SQL Express
License for BlackPearl + BlackForms
I wonder if K2 have some kind of small server license that allow k2 BlackPearl to be installed for small offices... or perhaps they have to wait until a web-based tenant of K2 is available for their usage.