Disappointed

So my bf came to pick me up for work (we work at the same place) and he goes when you go to open your gift don't pay attention to the price tag I forgot to take it off and then proceeds to tell me it was $15.. I looked at him shocked and was like okay.... I spent $60 on this man's gifts and now that I know he only spent $15 on me I feel kind of disappointed but didn't say that to him as I'm gracious for whatever I get but why do I feel disappointed about the fact he only spent $15 on me? He then tells me (without me saying anything to him) that he wanted to get me something more expensive but didn't feel like standing around for the store associate. I just said okay again and that was that.