All depends on what you need I guess. I just bought a Lowrance 600C for $499 as a backup for my in-plane Garmins. It's an incredible deal - for that you get the unit itself, including internal battery holder, yoke clamp kit, suction mount, auxiliary antenna, ship's power cable, ...
It's quite a small display, which in my case is what I want. I looked at another couple of devices which were much more expensive and then you had to pay even more for mounting hardware and the like.
The weather has been so cr@p that I haven't actually taken it up in the plane yet, but it looks as though it has all I need and more. Definitely a happy customer, so far anyway.
n5296s