<human>: Can you summarize the given text in a few sentences?

I have had my running shoes for a long time now. I do not run much, but I run approx 6 to 10 miles a week (starting back from not running for over a year). However, I have had my saucony trigon 4 shoes forever and think it may be time to get a new pair. I do not know much about running shoes except that this is the only pair I have had that my ankles and knees do not hurt  in after a run. When I do a wet foot test I have a normal pronation, I believe these shoes normally help over pronation, and when I look at the bottom of these shoes they seem to have even center wear on the ball of the foot, and slightly outer back heal area (so I assume they are right for me and my form). Does anyone know what shoe I should go with? I honestly got these for $20 brand new from an overstock store and am not looking forward to paying big bucks for new shoes, but it is better than an injury. My main question being, should I just search and buy the same pair I have or should I "upgrade?" , and if I go with a say saucony trigon 5 is that just the newest version of what I have?
<bot>: need new shoes, should I purchase same pair I had (since they seemed to work well  for me?) or should I upgrade, and if so what to?