Re: I have about 500 or a little more on a fish finder
Well, we need to know a little more before we can advise you what to get. You need to determine what are you going to use it for and what are your normal conditions.
Fishing, depth finder or both?
Lake depth (units have max depts, my old unit will not work in some deep lakes I frequent)
Mount preference, thru hull, transom
GPS combo...
There are more, take a look at any of the large outdoors stores and check what they have online, read the information. That will help you narrow down what you need then maybe we can help you "fine tune" your decision.