Raytheon RL70 Radar/Chart Plotter C-map cards

[JulianGullsway]

Hi All,
I have recently acquired the above which I initially brought just to use as a radar until I realised its potential as a number 2 Chart plotter for the cockpit where as the first is on the chart table, however I started looking at the cost of the C-Map cards which I would need to use as a chart plotter, I was wondering if there was an alternative as they seem very expensive, any suggestions or ideas?