Not just Nike wrote:
Why are they going up in price? Because the shoe companies are using new ideas, better materials and better designs, so the price goes up. It's life.
That's kind of a joke. For all of the big shoe companies you're paying for the brand more than the actual cost of developing and manufacturing the shoe. It costs a couple of dollars to make a shoe. The vast, vast majority of the company's expenses are incurred through advertising, such as paying douchebags like Armstrong, Pistorius and Marion Jones millions of dollars to showcase their products.
Of all of the shoe companies, Nike seems to have the least integrity in choosing athletes to sponsor, not to mention incidents such as the Mark Block fiasco. Obviously none of the shoe companies are exempt from criticism but, to the OP, I'd choose to support any of them over Nike.