Although Rumples immediate reaction when Belle kissed him was to freak out when he learned that EQ had told her that kissing him would break the curse, the more I have watched Skin Deep the less I believe that he chose his power over Belle.
I think that after all those years of living by himself and only being wanted by other people for deal-making, that he and Belle had created somewhat of a “bubble” for themselves living together in the castle for all those months. I think that even though he got Belle in a deal I think he thought of her as totally separate from his magic/power. I doubt she went with him when he went to do any of his deals and he behaved much more humanly around her than he did when he was making deals. And in conversation she talked to him about how he wasn’t a monster and reminded him that he used to be just an ordinary man. So I think in many ways he started to feel very much human around her and started to believe that she actually was falling in love with him. So when he tested her by allowing her to leave and she came back I think he was at his most vulnerable with her when he asked her “Why did you come back?” He’s in shock because he couldn’t believe she would come back but deep down he really hoped she would (and he waited by the window all day!). And then she kisses him and he thinks “OMG she really does love me!” And then she mentions the him changing and the EQ and rips his heart out (no pun intended). I think at that point he is suddenly shocked back into the realization of what he is and is completely and totally emotionally crushed. I’m guessing that later he realized that Belle honestly had no idea who EQ was but he is still horribly, emotionally wounded. So when he tells her that his power is more important than her I think he says that because it is the only thing he has that he can say to purposely hurt her. He has nothing else in his life besides power/magic so the only thing he can use to hurt her with is power/magic. He loves her too much to actually DO something to her so he decides to hurt her emotionally the same way she crushed him emotionally. You know how some people do that? Some one will say something that hurts them and instead of telling the person they were hurt by their comments they will turn around and try to say something even more hurtful back to get even? That’s what I think Rumple did. And that’s why I think he is so guilt ridden over Belle. He really didn’t mean what he said and regrets that he said it. Hence, when EQ tells Rumple that Belle’s father kicked her out he is ready to go get her. Someone pointed out somewhere that Rumple says “So she needs a home?” Not “She needs a place to stay?” or “She has no where to go?” He uses the word “home.” That implies that he was ready to go get her and bring her back “home.” Like they had a fight and he is ready to go make up. Those aren’t the words of someone who is choosing power over someone they love. Now he may have a reason that he needs to remain Dark One Rumple (like to get Bae back) so he might not be able to kiss her but that doesn’t mean that he is choosing his power over Belle. He could have had both if she had approached it better.