Are there any descent cheaper fishfinders out there ? My boat came with a Lowrance elite 7HDI and a Hook 7 . The hook 7 is ok i guess (but very slow) but the 7HDI is a piece of crap ! i need to replace it on trolling motor , but dont care about spending a ton of money . anyone have any suggestions for a descent one that doesnt cost an arm and a leg ? i just need to have basic functions , thanks