I understand your reasoning, and may even accept it, but don't fully agree with it. If i would search for the price of an item, i would rather like to know how to calculate the correct value from the base price, than some estimated amount. But we can provide both information of course (so i should create a page about how to calculate prices :).
Ok, you say that store prices should be listed at Rep 10 and Chr 10-12, i can live with that. Note that you used selling price in your above example, which is not based on reputation and charisma, but the amount of same items at store and some vendors give better prices than others. So should we list selling prices as new sell (no similar item in store) and a generic store?
A further complication about prices, that the same item could have different value in different editions/parts of the game (or so i assume, i can't give a particular example all of a sudden). This could be handled maybe by the same way as by the way ammunations "max. stack"?