I don't believe he is a lost cause, nor do I believe he is beyond help. I don't think that's true of anyone. I do, however, think he is beyond *your* help.
I believe that if he is who you say he is, then he is more than capable of achieving sobriety and recovery without the incredibly huge red flag of this condition: "If only I will bail him out so he can start building a life with me again and find recovery again."
Do you see the conditional and transactional nature of this? Do you see that he is offering you exactly what you want in order to save himself from the consequences of his own behaviors? He had a gun and was attempting to distribute...something (drugs, I assume?). I get the comparison you are trying to make with a soccer mom with a gun who isn't punished as severely, but he did this thing knowing the consequences due to his convicted status. Our system might be broken but that doesn't change what is happening between you and him.
The man you describe in your second post sounds resourceful and capable, whether or not you open yourself up to more disappointment. He doesn't need you to recover. AA is free. He doesn't need you to save him. Your support doesn't have to be in the form of money, or a place to live, or anything more than an "I believe in you." Instead of him making his recovery conditional on you being a part of his life, why can't you make him being a part of your life conditional on his recovery? If this relationship is worth having, it will wait a year while he sorts himself out. At least.
Of course, the choice is yours. I hope that whatever you decide to do, he takes this opportunity to find what he had before, and that if you decide to re-engage, that you have find nothing but the greatest happiness, because that is what you both deserve.