Buy what you can afford. Alot of folks run Eagle 320 or 480 units up front and I think they run in the $125-225 price range. Also you can buy both Humminbird and Lowrance products in that range and a little higher money wise and they should serve you well. I use my front unit more to identify depth & structure and try to ignore the fish symbols if at all possible. BTW I run a HB 717 up front and like it pretty good.