http://shop.delorme.com/OA_HTML/DELi...§ion=10461
$299.99 is the intro model. When I say intro, it doesn't mean it is weak. It just has a few less bells n whistles than the higher two. Unless you need a barametric altimeter or SPOT on the unit, this will do. It comes with topo, streets, and another then for $29.95 a year you can download all the lakes, satelite over lay like google earth and drop a Navionics chip in there.
Most are $99 for the topo maps or lakes or whichever added software.