Gedunk once bubbled...
Does anyone honestly think there is really such a thing as free estimates? Whether you believe it or not someone pays for the overhead it takes any business to provide "free estimates." It might not be you if you don't accept the estimate and purchase the goods or services but it will be the next person who does.
This is true. So by not having to pay for those missed bids, one is essentially charging the customer for costs he didn't incur. This would be less than honest. If a contractor wants to have a higher profit margin, more power to him. If I know better, and the contractor tries to snow me into thinking it's overhead and not profit at the start of our business relationship, how can I build a trusting relationship with someone that is trying to snow me from the get go?
His other option is to lower his total base bid which will put him in a more favorable light compared to other bidders which greatly reduces, if not eliminates the risk of me wasting his time and then going with another contractor.