Currently, feed store price is 16.25 per ~90lb bale leafy alfalfa, 18.50 for grass, same weight. Growers are at about the same - no telling how that works. The only way to beat these prices is to lease/buy a field and grow your own or buy by the semi load. So, I pay the price and try to buy ahead for winter....and eat just eat oatmeal w no butter or sugar to help offset the costs.
I just have to say, all hay is not equal. I have had my horses back east, and what is considered high quality hay there cannot compare to alfalfa or select western grown grasses (nutrition and calorie wise). So, it takes a lot more of it if that is all the forage in their diet (i.e., not on pasture). Don't get me wrong, it is significantly cheaper to feed a horse there - but not quite as "less expensive" as just hay prices would predict.