There's nothing wrong with giving or receiving gifts - between 2 people who know and love each other and have an equal and supportive relationship, there's no obligation involved.
An example. I am really bad at picking gifts for people and often miss the point completely if people drop subtle hints in the run-up to their birthday, but over the weekend my boyfriend moaned at some length about the fact that he couldn't afford to buy a CD that he really wanted. So on Monday I stopped off at the record store on my way home from work and bought it for him because I could afford it and I knew he wanted it. I sometimes have trouble expressing the fact that I care about him, but buying him a gift that I knew he wanted was one way of me showing that I care. I don't expect anything in return, and I'm not trying to buy his love, just doing something small to make him happy.
It doesn't have to be a gift, if I were to cook dinner for him could that also be considered buying him, or leaving him with some obligation towards me?
I am aware that I lack the ability to notice if he is feeling down/stressed/tired etc unless he explicitly tells me, so on the rare occassions when I am sure that he would be pleased if I did something for him - be it a small gift, cook a nice meal etc, then I see it as part of being in a mutually supportive relationship to do so, nothing more sinister than that.