Fish Finder Advice

OK, i am at at the point where i want a depth finder.  Mostly i just want to know depth.  I figure $79.99 for an X-4 Pro sonar, Garmin 150, or PMax 170 from Cabelas Bargin Cave. 
Do i really need anything more?
which of Those three is the best?

OK, i am at at the point where i want a depth finder.  Mostly i just want to know depth.  I figure $79.99 for an X-4 Pro sonar, Garmin 150, or PMax 170 from Cabelas Bargin Cave. 
Do i really need anything more?
which of Those three is the best?

The X-4 Pro is probably the best of the three.  Garmin 150 would be a close second.  IMO the pmax series are too fragile.

Any one using the Echo 150 by Garmin?

2 words = Bomb Proof!

you are right about "needing anything more", you really dont.....this one has seeing fish for five years now = NO Problems! 
bottom is what you want to know at first, then once you see them fish and drop on them,,,and they acually bite back, you will forever be hooked on finding those fish on the finder first.

i think you can get them for that same low price ($70-80) if you look around.

I have the pmax, it's done well for me as long as you keep the electrodes coated in dielectric grease.  I can't see spending hundreds of dollars on the high end units, I mainly just want to see the depth, bottom structure, water temp and let my fish vibes take it from there.