Men with a vasectomy or reversal... should i stay or should i go?

my boyfriend has a vasectomy. he got it before we met due to the fact that he has 3 children already. i don't know if i want children, but he is a great father so i know if i would want one, he would be a great father to our child. we've talked about it and he said if we were to get married and our finances were good, he would like to have a child with me if thats what i want. he basically got the 'snip' after he got divorced because he didn't want to have any surprise babies. he loves children and said as long as he can/could afford another child and was married, he would have another one. i've heard the cost for a reversal can range anywhere from $5,000 - $13,000 and that the chances of me getting preggo are lower... what other options are there? taking the little soldiers from him for i.v.f.? and what are the odds of that working? he is an amazing guy and i could see spending the rest of my life with him. but if i do decide i want a kid, do you think he'll go through with it?