I was in the US for 6 months when Ds was aged 2-8 months.
We had the prevnar as meningitis is so scary. We were only there long enough to get 3 of them instead of the usual 4 (the 3rd one he had just before we left even though it was a bit earlier then they usually give them). The paediatrician said that 3 jabs gave very good imunity so was worth having even if we couldn't get the full 4 so we went for it.
Men C is not given in the US at the moment so I caught up with that when we got home.
In the place we were they gave individual injections for polio etc so DS had 5 jabs at once each time he went. I was too much of a sensitive mum and said to withhold the hep b as I didn't think a baby needs it until later and hated seeing him cry at the injections.
Anyway when we got back a nurse asked if I had had the hep b jab in the US as the health professionals in the UK are lobbying for it but the govt thinks it is too expensive at the moment. She said it was really effective and would prevent a lot of young adults getting hep b. Anyway I now wish I had given DS the hep b jab as well.
One thing though - as we were only there 6 months our health insurance was quite basic so had to pay for them and prevnar was very expensive at $90 a shot. Then we found out that they would give the injections cheaply ($14) if we were not covered by insurance. They made a loss on this so I really don't think that the money is the reason they offer injections. Doctors believe they are necessary and important as do I.
Assuming your child doesn't get bad reactions (mine doesn't) I would get as many as are offered (assuming the immumity they give is worth it).
Most vaccinations need more than one over a minimum period of time to be effective.
Anna