Any clever business owner knows that it is all about 'Swings and Roundabouts' - you may miss out on the swing, but catch the roundabout and goodwill is a highly valued commodity.

I have two local LBS and have a good relationship with both of them, to the point where advice is freely given and discounts always provided on purchases. I do 99% of my own work on my bikes and do frequent online components suppliers, but if I need anything urgently, I purchase locally.

I have also recommended the shops to friends who have gone on to purchase bikes and other equipment from them. I tend to drop-in fairly regularly to have a yarn and a laugh, which is always accommodated and both owners/staff participate in regular local rides and the local club. The relationship is fairly symbiotic.

Getting back to the OP's question, the minor inconvenience of providing that assistance could yield dividends in the long term and a shop owner would be silly to try and charge for such service.

cheers