No, I don't think it's worth his family (I don't think it's right for anyone to do drugs o even sell them - there's always someone who gets hurt/killed in the process).
He might've originally done it for his family, but after a while, it just became all about him and wanting to make something out of himself. To do something he was... well, something he was actually good at.
He was great at chemistry.
He wanted to be remembered... and not treated like shit, as he was treated in the beginning of the show, before he even discovered he had cancer.
In the end, though, he did give Walt Jr. that money and he saved Jesse from those neo nazi guys (even though Jesse was there because of Walt).
I believe Walt cared... but wanted power, to have things his way, and be in control of his own life.
I think Walt's life was worth saving, but he could have got help from Elliot and Gretchen. He didn't have to sell drugs he just wanted to be the hero that brings the money for the family instead of his old accomplices doing it.