When should i let my BF pay?

My bf has never celebrated xmas properly because he is foreign. I told him i really wanna get a christmas tree. hE SAId if i really wanted one, then we would get one, despite the mess. I am buying all the decorations from the lights to the ornaments to the tree skirt... the tree will be anywhere from 50-100$. i am about spent for the decorations.. sohuld i let him buy the tree? i think he wouldnt let me pay for it anyway