Different Campaigns and Characters call for different ideas. I see no reason to attach a stigma to wizards/item creators just because they charge book price.
Take for example, Lucifus Cray, the high level alienist that I play. He would charge anywhere from cost up to several times book price depending upon the client. Whichever the way, he would always ask for a favour in return. This could be anything from arranging a meeting with a "special" person and ranging to some of the more bizarre requests I have seen played out in a game. Sometimes a favour to Lucifus Cray is priced at an exorbitant cost. Most of the time, it would just be simpler for party members to get their stock standard stuff elsewhere - part of Lucifus's design behind his pricing scheme. Occasionally though, he would be motivated to surprising acts of generosity. Others times not.
There was one time when somebody claimed the price was more than his friend paid elsewhere. To this, Lucifus replied that perhaps the quality of the friend's item was not quite up to scratch. I mean you can get it made by some base cleric who follows some strange and bizarre dogma or you could purchase it from one of the greatest arcanists gracing the lands of Urth. As arguing with high level wizards is neither wise nor good for one's health, most clients were just happy with their "superior" version.
Alternatively, in the upcoming Age of Worms campaign that I'm running, the book price is considered standard across the board. To cheapen one's work by wholesaling it off is NOT the behaviour of a true wizard - although other classes might not be so strictly governed. As such, wizards may choose to gift their items to another but never sell them at half price or bogof. It's all in the wizardly mystique you see.
Best Regards
Herremann the Wise