Quoted from Crash:About $260, including a $7 micro USB 5v power supply and $2 heatsinks for the Raspberry. Considering this setup has a much longer life than a plasma DMD, doesn't use problematic high voltage parts, and is just over half the cost of a ColorDMD, it's a very feasible price.
Good luck! Glad I could help.
As an outspoken supporter of the DMDExtender product, I don't think it's necessarily appropriate to refer to it as a "Poor Man's ColorDMD" which implies it's not as good... It has a lot of flexibility that ColorDMD doesn't offer such as the ability to choose 4 custom colors for each shade of the dots from the original DMD and the ability to add in additional displays.