I got my Garmin 540S off or e-Bay for $580 which was the lowest price I could find. It came with the dual frequency transom mounted tranducer. The Garmin Bluechart G2 for our area was $240. Haven't used it on the boat yet (still frozen in) but have booted it up and works fine. Easy to understand interface and controls.
Yours Aye! Rick
"It's not the boat "you built" until you've sworn at it, bled on it, sweated over it, cried beside it and then threatened to haul the POS outside and burn it!"