Under the GST law, consideration can be in “money or otherwise”, and also includes the monetary value of an act or forbearance, in relation to a supply. Consideration may also flow from any person other than the recipient. In cases, where the money received in respect of the supply is not the sole consideration, the “price is not the sole consideration”. E.g. Buyer of capital goods discharges the loan of seller, goods purchased on exchange offer, etc.
(ICAI FAQ PUBLICATION 06-09-2017 VALUE OF TAXABLE SUPPLY : FAQ NO. 49)