I'm new to this, I've run quite a bit in the past, but never in any dedicated fashion! Looking for some new trainers to get now the weathers getting nicer so I'll be out more. Is it worth investing in an expensive pair? Or even going to a shop and having my 'gait' monitored or whatever it is they do! Do people find cheapish ones ok? I really want a good pair, but don't want to spend so much.