Relief. In the event that an affordable unit cannot be sold or rented, as applicable, the owner may apply to the Affordable Housing Board for relief. Relief to the owner shall not include exempting the unit from the required moderate- or low-income sale price or rent level, nor shall relief include exempting the unit from restrictions on escalation allowable upon re-rental. However, the Affordable Housing Board may allow the owner to sell or rent the subject unit to a household whose income exceeds that otherwise required, provided that in no event shall an affordable housing unit be sold or rented to a household earning in excess of 80% of the applicable median income.