This is just one of those choices in life that you have to make and live with the consequences. You will always get contradictory statements and answers when asking these kinds of questions. You would get the same when asking about tyre repairs - some will say yes, others will say no. Both answers are correct because its down to personal choice. There is'nt a law to tell you what to do. Its your head and your life so for everyone else its an easy comment to make because their life is not affected either way.
For the record, if I dropped my helmet and heard a sharp "crack" I would replace it. I'm worth more than £400 which is what I might end up paying. I will however repair a rear tyre puncture myself and ride it until its worn out. I will also repair a front tyre but in that case I will get the tyre replaced at the earliest opportunity. These are my choices and based on my own personal "Risk Assessment". You will need to do the same.
