A magickally charged object ( i.e. a talisman) to be fully efficacious should never be sold, lent, coveted, obtained by fraud or force. To be fully effective a magickal object has to be given as a gift from a maker to the client. It is a symbolic operation and conventional fixed pricing is not involved here. A person who receives the 'gift' must then offer a reciprocal gesture, as a payment for the service. Usually it is the 10th of the efficacy value (EV) of the talisman. Here's an example, say a client needs a talisman with the value outcome of 10. 000 $ (i.e. a start-up of small business venture), in this case his/her reciprocal gift to the magician should be 1000 $, which is the 10th of the 10.000 $)
Another important point to understand when personally determining the value of the service: The price for the efficacy of the object is symbolically addressed to the spiritual entities that partake in the creation of the talisman. Technically speaking, they feed off the energy of the client's offering. When we make deals on spiritual levels, any attempt to covet or cheat the real value of the service will be immediately registered (not necessarily by the magician, but by the spirits involved) and subsequently annul the magical potency of the object. In other words, you can't cheat spiritual forces. A spiritually dishonest client would end up paying for a spiritually useless object.