(a) Notwithstanding the definitions contained in section one-a of this article, for purposes of this section:
(1) “Contribution” means a gift, subscription, loan, assessment, payment for services, dues, advance, donation, pledge, contract, agreement, forbearance or promise of money or other tangible thing of value, whether conditional or legally enforceable, or, a transfer of money or other tangible thing of value to a person, made for the purpose of funding the rental, purchase, construction or financing of the lease, purchase or construction of a party headquarters, and for the utilities, maintenance, furniture, fixtures, and equipment for the party headquarters. An offer or tender of a contribution is not a contribution if expressly and unconditionally rejected or returned. A contribution does not include volunteer personal services provided without compensation: Provided, That a nonmonetary contribution is to be considered at fair market value for reporting requirements and contribution limitations.