Worst Marine's got the 527 DF for 700 so if ya got 'er for 650 ya did OK...probably coulda done better pricewise on E-Bay, but I wouldn't have gone there either... the A-Hole in BW oughtta be tarred & feathered ;) ... yer gonna like that unit...it's an updated version of my 337 ... 8) ...
If ya wanna learn how to use it, get your Owners Manual and go here:
http://www.lowrance.com/Downloads/Emulators/default.asp
Find your unit, download it and you can perform any function ....