We are in a similar situation, by the time we could remotely afford another ds would be going to school. I would have preferred a smaller age gap but I can't see it being possible.
Also, it took a long time for ds to arrive and we don't know if it will be the same second time around in which case we'd need to start now!
Our house size isn't ideal either and it's not about having a big house we only have two bedrooms and one is a single room so that's another factor.
We also need to think of childcare, ds goes to nursery for half the week and my Mums the other half...we are so grateful she is able and willing but she is 73 and I recognise this wouldn't be the situation regarding help in nearly 4 years...ds is 16 months just now.
I understand where you're coming from, I sometimes wonder,even though we would both love another, that we could provide better for ds if we stopped at one.
It's not an easy decision but a lot can change in a short space of time so Im trying not always succeding to not consider it too much right now.
DS is 9 months old, and is our world (pfb!). We will both be working full time, and ds will be in nursery during the day. Money is extremely tight, but manageable. We have started discussing about when or if we are going to have a 2nd baby. We will need to wait until ds is about 2, so if dc2 comes along, ds1 will have his free hours at nursery etc. However, dh and I are torn. The decision is do we have another DC, or do we just concentrate on ds1, and give him everything we can? We would love to have dc2, but the money side of things is a real worry, and would be stretched even further if we had another child. I just wondered if anyone had been in a similar situation, and if so, what you decided?