There once was a day that one finder brand was better or easier to use than another. It does not seem to be true today, they are just different. If you know how to use Hummingbird, then stick with it, but Lawrence and Garmin are also good.
The prices depend on which features they have and how big the screen size is. But, don't let the screen size fool you. I could not get the 9" to fit under my windshield so 7" is my limit. Measure well so you don't find that you have a huge screen and no place to mount it.
As for features, most of the newest units use a multi-frequency beam now, something that 'Bird calls C.H.I.R.P. It gives far more detail then the older 2 or three frequency units. Make sure that the unit has this new feature.
Next, GPS. I won't have a unit without it. With GPS you can locate proper depth and structure changes if you are a "structure fisherman". Marking "hot spots" or trolling paths, is also a great feature. You can also use it for navigation in the fog, or at night. My first few units did not have it, but when a bank of fog rolled in on me on a giant lake in Northern Idaho, and I was lost for about 4 hours, I had a GPS the next day. Did I mention I won't have a boat without a GPS enabled finder? LOL Now, if I am in cell phone areas, or on a tube, or a handheld GPS, I guess I could live without it.
DI or down imaging is awesome, once you learn to read it. The detail they provide is incredible, but if you are not a bass or walleye fisherman, I just don't think it helps that much. I am not saying I don't like it, but don't spend what you don't need. You will not see trout setting on the bottom, or catfish belly to the mud, but, once you learn to see the "shadow", you can see them better then with a regular unit in the tree branches or rock piles, or just over bottom.
Side imaging is also excellent. It still shoots a cone down the sides at an angle so you will not see shallow fish off to the sides, or fish directly under the boat, but if you are trolling for Lakers, Kokes, or other schooling fish, it can really help locate fish that are moving away from the boat. Again, it is awesome detail, but you are looking for shadows, not arcs on the screen. It takes some time to learn to use it. It is not necessary, but it is useful.
OK, for the most part, if you have a unit with two or more of the features above, then you will have split screen features, but it is important to confirm it. You must confirm this. It really is a good idea to be able to see the lake map, the down imaging, and the side imaging at the same time.
Many units have one or two features, but getting all, or most, of them will probably require ordering it in. But, with your price range, you can get an excellent one.
One last piece of advice, if you go to Store X and they have it on sale, it is almost certainly an old unit, one about to be, or has been, replaced. The store profit on the units is so small that they just don't do sales unless the units are being upgraded. Still, if the older model does what you want, and you don't need the newest technology, then last years model is so much better then the old unit I have on my boat.
I hope that this helps some.
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