I have two pairs, regular all rounders and some trail shoes that I bought from a cut price sports retailer when I was doing C25K over a year ago now. They have been fantastic at around £30 a pair and seem fine. Admittedly the trail shoes have not been worn as much but the regular shoes have covered a lot of distance. I added up what I have done just from January to today and it is 236 kilometres so that doesn't include C25K or the rest of last year! I am a little sentimental about them though and they are still very comfortable. When is it time to think about a new pair, I am worried a new pair won't be comfortable or could even cause an injury!!