I just passed our local K-Mart yesterday and they had good sets for as low a $150 (4 padded chairs)
Be sure you get aluminum - not steel! Aluminum won't rust!
I worked at Sears in college and got a really nice set for $69.00 at season end - they had to sell it to get the Fall stuff on the floor- that was about 8 years ago, and the set it still going strong. A few dents/dings from storms over the years, and a few cracks in the finish- but since it's aluminum, it won't rust!
It still looks great!
Now is definitely the time to buy!