You can get some cheaper ones that are pretty decent for about ~150$.

https://www.amazon.com/Eyoyo-Portable-Waterproof-Underwater-Infrared/dp/B076LXGGBT

We used this one this year and it worked pretty well.

Had some issues with it during low-light conditions but I think that had more to do with the lake we were fishing because it's pretty dirty.

Only thing I'd say is to make sure you get some sort of method of "turning" the camera and keeping it steady (As opposed to just using your hands to "twist" the cable). I just use a folded up coat hanger personally.

Eyoyo Underwater Fishing Camera $28 off on Amazon https://www.amazon.com/Eyoyo-Portable-Waterproof-Underwater-Infrared/dp/B076LXGGBT

ReelSonar Wireless Fish Finder $27 off on amazon https://www.amazon.com/iBobber-Wireless-Bluetooth-Android-devices/dp/B00LEA2FS0

Lowrance 5 Inch Fish Finders $92 off on amazon https://www.amazon.com/Lowrance-Reveal-SplitShot-DownScan-Plotter/dp/B083PVQ356