I have purchased many a pair of training shoes, and have never gone wrong when I spent at least $50. I am not a big runner, so that might be the reason. No particular brand has ever stuck out over another. The big difference has mainly been in design and style.
Nike is the the brand I am least familiar with as I don't care for the company. It's possible they actally do have weak shoes that only look nice, I don't know. Only had one pair.
The cool thing about NB is the spendy ones are likely made in USA.