Spend the extra few bucks on the Warn...you go cheap and it'll most likely leave you stranded that one time you need it most. And then once you pay the bill for the towing company to winch you out, you'll realize it would have been cheaper to have bought the Warn which will last for years.
I believe the Warn M8000 is $539 shipped from http://www.winchdepot.com
only $39 over your upper limit and it won't leave you stranded.
One thing to keep in mind with winches..you get what you pay for. Buy a cheap winch, the quality/reliability is going to reflect that.