"RE: fish finder?"
Ah, that would be me!!
I am fish finder extraordinaire!! lol I'm cheap too! After 0ver 50 yrs of serious fishing all over these United States, I can guarantee you that i will "find fish." No chip or GPS required.
In all seriousness, yes i do fish a lot but my game these past 20 years or so has been pretty much limited to Trout and Small Mouth bass with good sized trout getting the nod. We use the fish finder not so much to find the fish or the bait fish that they feed on. We already know where they are in most cases. We mostly use it for depth and getting an idea of the bottom structure but most any unit you could buy marks the fish as well.
Finding fish and getting them to bite are two hugely different and most important things IMO. We have been "on" thousands of big trout for hours at a time, dragging our best and proven killer offerings, right in front of their noses and knot
get a single bite!! Other times they try to destroy our equipment and near jump in the boat.
I Believe cheaper named brand units will work just fine for most peoples needs. I'd not get the "better" or "best" quality one unless i had the money to burn and time to figure how to use the thing! Put your money in good rods, better reels, keeping on fresh quality fishing line, and really sharp quality hooks...and knots! Learn and use the best Knots for each application. That's money well spent IMO, and if you can ever figure out why fish, just flat out won't bite, i'd sure like to know!!
Joey