请问这句话是虚拟语气吗?

请问这句话是虚拟语气吗?
he would have paid twice much as for the house if the salesgirl had insisted because he really wanted it
那天我查看if引导的虚拟语气的语法内容。说在主句中的should只用于第一人称，would可以用于各种人称。可是例句中又有if he should come,i would tell him.he 是第二人称啊。