In determining the amount of tax due on the use of a service it is presumed, in the absence of preponderant evidence of another value, that the value means the total amount of money or the reasonable value of other consideration paid for the service exclusive of any type of time-price differential. However, in an exchange in which the amount paid does not represent the value of the service purchased, the tax shall be imposed on the reasonable value of the service purchased.
SDCL 10-46-18.2