I don't know, OA .... I paid over $475 for mine and think I got a good deal. You can find them cheaper, now, if you look hard enough.
I've got a lake that has 200ft depths in it, and 80-100ft depths not a boat's length from shore ... but never have had to fish it deeper than 30ft. And most of the rest of the lakes I fish will have a thermocline develop @ the 15-20ft depth, in the heat of Summer. So I just keep the range set at 40ft & pay no attention to the bottom disappearing ... my baits are not going to be any deeper than ~20ft, anyway. I'm looking for the tops of cover sticking above the thermocline layer, or bait balls or schools of fish to come on screen .... regardless of bottom depth.
Even in 30ft of water ... the sonar beam is ~25ft wide on 800kHz .... and ~45ft wide on 455kHz
In the "more likely" category of the small lake "wackyman" is fishing, he'll probably be finding fish around the 15-20ft depth range. The sonar beam would be over 16ft wide at 800kHz & over 30ft wide at 455kHz ... in just 20ft depths. He shouldn't have any trouble getting images like this:
Attachment 127851
(and that's not zoomed in, either)
... cp