Cheap heater for heating 5 to 10 gallon buckets

So my cheap little heater that I have been using to heat water gave it's last gasp... though it's been a bit messed up for a while... it's auto shutoff function hasn't worked in ages... so I accidentally heated my saltwater to 112f once oops... back to the point... any one know an acceptable one to use... i don't need fancy bits on it... just to heat water to 80ish... doesn't even need to stop there... I'll check on it regularly like I have been doing... :P thanks