My latest contribution. I picked up a 2007 Northstar M84 headunit
with a C-Map chip of the local area from a local 2nd hand/consignment store, he had it on sale for $350, I paid him $100.
I then managed to locate a compatible Navman GPS receiver in another consignment store, $20, some aluminium bar ($6) and a TV mounting arm from a local electronics place going out of business ($25).
I fabricated a mounting bracket and fitted it all up today, didn't even have to run power to it as I had left the wires in place when I replaced the busted depth sounder with the bargain TackTick unit.
I now have an 8.4" colour chartplotter/MFD for a whisker under $160