One idea that I am exploring (both for personal use and as a product) is to use a small "netbook", such as Eee PC with a chart software product. As a user because I would enjoy a system like that on my boat. As a product because PolarView (to which I am partial, of course
) is designed in part to run on systems of that type.
At a cost of about $300 per machine with a 10" screen it makes a fairly decent navigation system supporting both ENC and RNC charts. A dedicated plotter with the same size screen would cost at least 4-5 times more and require charts that cost money too.
The drawbacks compared to a dedicated "hardware" plotter (like my Garmin) are lack of waterproofing (which means it better stay down below) and screens that aren't as easy to read in sunlight (though some netbooks have pretty decent backlight since they are designed for use on the road). Power draw is higher too, but netbooks are fairly miserly relative to other machines and quite reasonable overall. Dedicated plotters also tend to have more integration features (radars and such) but at the same time may not support GRIB data or, for example, provide connectivity etc, so I suppose functionality-wise it may depend on the target user.