I just bought a grumman cheetah with original 6 pack gauges. I was wondering if there is any budget friendly GPS and displays with cdi like the G5 or aspen units. The club plane I use to fly the owner put a aspen and garmin (not sure which model) and said the price was over $30K with installation. Is this about the normal price for a upgrade or can you get it done for alot cheaper? Im not looking for a full glass cockpit just the basic GPS unit with a digital attitude and cdi I could shoot RNAV approaches with. TIA