I was in your same situation last year, I think this model has been discontinued however if you can find one, its WELL worth the money ~$200. I bought one last year and have been nothing but pleased with it. The GPS chartplotting is outstanding for a unit this size and price, while you can not update the maps on it how often do things really majorly change? It has a good depth / fish finder as well with temp. I really cant say enough about it. It has all the major features, tides, moon, all the markers on the river (where I am atleast), route planning, all the data you could really ever need, and you can overlay the depth and temp data on the chart or the nav info on the depth finder, it does split screen...I could go on. Although I don't think it shows marinas, check a paper chart, then mark them as a waypoint on the unit, I always have a paper chart as a back up anyway.
Here is a link to a site that looks like they have them in stock and also a feature list. Might also check ebay.
http://www.johnnyspond.com/eacu250scoso.html
manufacture website, check the manual, it seems kinda overwhelming at first, but its VERY easy to use.
http://www.eaglesonar.com/Products/Combo/Cuda250SMap.htm
good luck!