As cheap as possible, really. Stock quality is good enough. $50 for all four?

I went to Best Buy today to get an in-dash installation kit for the new head unit. The guy told me that probably wouldn't work since the in-dash kit is made for after-market head units which are smaller that the OEM.

Any idea how to mount a newer Honda head unit inplace of the old one?
The electrical connections are good: I have already installed a wire harness.