A secured party who disposes of collateral under section 128 (other than by purchasing the collateral) owes a duty, to any other person with a security interest in the collateral, and to the grantor, immediately before the disposal, to exercise all reasonable care:
(a) if the collateral has a market value at the time of disposal--to obtain at least that market value; or
(b) otherwise--to obtain the best price that is reasonably obtainable at the time of disposal, having regard to the circumstances existing at that time.
Note: A different rule applies in relation to disposal by purchase (see subsection 129(3)).