wow, quite a delimma. i would think you both want to eventually be on the same page with this.
my husband and i have his kids and our kids (total of 4 living with us - 2 teens and 2 toddlers)
we are still in grad and law school, so we decided it was ours and the children's best interest not to have anymore. We need to get through our own schooling and by the time we do that, we will have to put 2 kids through and after they're done, we will have 2 more to put through.
as you can see, we will be broke forever! lol
i want them to actually have a better chance at living a better life than we did. neither of our parents help with tuition or even pushed me to get through school or encouraged him to go to school. Now we are making up for lost time. otherwise, we would already have careers and would be in a better position to raise and rear our children. In the end, i hope they do not have to worry as much about finances as we have. if that means we take the grunt of the expense, we will do it.
so many parents are into this 'making the kids responsible and independent' that they are not able to support them as they should. my mom says she supports me, but it is only how, when, and to what extent she sees fit - this doesn't really help because there are always strings attached and my plans are definitely not the same as hers (for very valid reasons that i do not want to and should not have to tell her about). if you want the best for your children, then let them actually live and make decisions and give them the help they ask for without changing their options because you are unwilling to help them or worry so much about your situation that you jeopardize theirs.
it is difficult to make these types of decisions, i know. but you both have very valid reasons for having and not having children. counseling might help bring out the underlying concerns about each. There are probably more concerns than those on the surface that each one of you need to see.
As i understand you would like a playmate for your child, if you decide not to have anymore, there are things you can do to eliminate the 'only child' syndrome.
once you become friends with people who have other children, he will probably gravitate to some as you did your cousins, etc.
Other children, hopefully ones you enjoy to be around as well, will become like brothers and sisters to him as long as you get together with them enough.
also, joining a church or other organization typically provides more stability with the relationships you and he builds.
good luck,
B.