Being as no one has responded, I'll stick my 2 cents in. I have an HB 565 which is no longer made. I believe the new version is the 570. Price range is right for what you stated. I have yo tell you of another that would save you a later upgrade and would give you a much better unit for about $100 or less over your budget. It's the 570 DI. It is a sonar and a down image in the same package. Look it up on Humminbird.com and you'll see the difference. I've had my 565 for several years without issue, and I'm looking to move up to the 570 DI for the front of my boat. For a few extra you would be very happy.
Creativity is just intelligence fooling around