Well, I usually say you get what you pay for. However, when it comes to shoes, the mid-price shoes tend to be the best overall value. They are well built enough to do what a runner needs and to be durable but you aren’t paying for the flashy plastic and nylon designs. If you want those flashy shoes, you’ll have to pay more. If not, I’d look at something more in that mid-price range. If you want to stick with adidas, their Response and Supernova lines are very popular and fall into this range. I’d also suggest considering Asics, New Balance, and Nike’s Bowerman series as some shoes well known for taking good care of runners.
My one concern about those real high priced shoes is sometimes they are marketed toward the high schoolers who are focusing on “cool” instead of function. I’ve heard from a few people who have worn the real expensive shoes that they were not even as good in terms of function as the more moderately priced shoes. It seems like the makers focus on “cool” to the point of sacrificing quality sometimes.