For that price limit, get the Lowrance 337CDF. This gets you color fish finder, and GPS the transducer, paddle wheel, whole shooting match. Installation was a piece of cake. For charts, there's Nauticpath covers the entire U.S. its about 99 bucks, Or Navionics Gold (I got the one from Nova Scotia to Charleston @ $199.00) . The Lowrance will set you back about 680 - 700 depending on where you purchase it. This plus charts and you're still under budget.
I really like mine, the screen size and resolution are great, but what sold me was the Operator interface. I found it to be the easiest to use of all the units I tested. Want to see what it looks like? Visit
http://sempreveloce.tripod.com/id2.html
I have it in split screen mode left right, but you can have any combo you like as in upper/lower big/little just gps, just Fish Finder etc. I like the Navionics, but at this years Annapolis boat show, the new version of Nauticpath was awsome for Chesapeke bay area, and its half the price of Navionics Gold.
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