I really like the 120 dollar bad elf Bluetooth GPS paired with 50 dollar navionics
iPad app. It's as good as or better than any Chartplotter
GPS and if you include the cost of the iPad you're out the door complete for like 700 bucks! And you've got an iPad!
I don't have a 4G, just wifi
Now if only someone would design a standalone Radome with Bluetooth connectivity and an autopilot
with some sort of Bluetooth or cable connex to the iPad, there'd be no need for the MFD Chartplotter