Real property necessary for such airport may be acquired by gift, or by purchase if such municipality or county is able to agree with the owners of such real property on the terms thereof, and otherwise by condemnation, in the manner provided by law under which such municipality or county is authorized to acquire real property for public use. The purchase price or award for any property acquired for airport purposes may be paid by appropriation of moneys available therefor or wholly or partly from the proceeds of sale of the bonds of such municipality or county, as the governing body or county court shall determine, subject, however, to the general provisions of law for the issuance and sale of bonds of municipalities and counties for public purposes generally.