You'll have to go try the trainers on, or at least the person who will be wearing them, to check for fit and comfort. There are plenty of alternatives but there are just as many variebles that make one trainer better than another.
I've just had a look at the Nike website and at first glance I can't find anything under £100 for a neutral runner.
Really any trainer would be just as good if the fit is right. Expensive doesn't always mean better. I have a budget of £60 and I thought that that was a lot. I can't imagine spending more on a trainer. I do check out the sales and last years models though. If you don't buy the latest then you can always pick up a bargin.
