in应该是it才通顺
因为有evenif所以后句为虚拟语气hadtheyspentthemoenythemselves.是iftheyhadspentthemoenythemselves的变体if省略后had提前
句子为Evenifagiftisenjoyed,itmaynotbewhattherecipientwouldhaveboughtiftheyhadspentthemoenythemselves.
所以句子可以翻译为
即便礼物很令人满意,如果是收受礼物的人自己掏腰包,礼物也不是接受礼物的人想买的.