How to convince someone to let me get them a gift?

I have a friend who doesn't really ever get to experience what receiving a gift is like and I know this would make that person happy to get a gift as that is how most people do when they get one. My friend will not agree to letting me get a gift though; how do I persuade my friend to agree? (I have 2 reasons to get this person a gift, so not exactly spur of the moment either.)