Humminbird has some descent low end fish finders. You can get a black and white model for less than $200 that works alright. I've used mine for the last season and it does pretty well at depth, temp, and picking up structure on the bottom.
I think I have one of their 500 series fish finders.
It's a fact that 70 percent of the people who purchase heavier tackle do so with the categorical I just lost a huge snook! Einstein Hairdo.The other 30 percent have either Tarpon Fever or are sporting a hand cramped into a claw from a deepwater grouper.