HI, Most people have a whinge about money at some stage, often for completely bizarre reaons. I have been in sales for over 10 years before my business now and I know generally that when people complain about price, its not the price they have a problem with its something else, eg service, lateness etc etc or worse they have someone else behind them winding them up (ie 'you pay how much.....!!!) I agree with those below, its not your customers business how much you pay your staff.
I have often found that a genuine supportive chat helps, ie
'yes I know prices are moving up its ever so hard at the moment, my costs are up drastically too, my fuel has increased 20%, tax, labour etc etc, I'm sure much like you you try to protect your customers, for example we've only passed on a fraction of our costs to you etc etc etc'
Main thing is keep your sense of humour and persevere. Don't forget they CHOSE you to do the work for them.
Good Luck!
Os