Even in the first case, it is not necessarily true that your friend considers $ 150 to be mutual consideration for his services. (money.stackexchange.com)
Most importantly, they can help children learn about how to develop a friendship based on mutual consideration and respect. (petsforpatriots.org)
No party is obligated to follow through with «their part» in any scenario, and mutual consideration does not seem to be established. (money.stackexchange.com)