I know, the prices are steep. You might try looking at heaters for animal bowls -- think outside the box --- water has to be kept from freezing for virtually every farm animal out there, chickens, goats, you name it. Here are some links: http://www.walmart.com/ip/Farm...
There are some that are just the element parts that you stick in the water but I can't find them at the moment.
I am a strong believer in the simple fact is that what matters in this life is how we treat others. I think that's what living is all about. Not what I've done in my life but how I've treated others. ~~ Sharon Brown