I'd suggest checking with your PD or KKH doctor about whether it's really necessary for your baby's situation, because $300 is not cheap and worth understanding the reasoning first. My friend took it and her baby was fine after, no issues, but honestly she was quite concerned about the cost too and wished the doctor had explained more about whether it was essential or more of a precaution. Since it's a newer vaccine here, it might help to ask the doc directly what the risks are if you don't take it, so you can make a decision that feels right for your family.
From what I’ve read, RSV can be quite serious for newborns especially in the first 6 months, so that’s why more gynaes in SG are recommending the vaccine now 😊 It helps pass antibodies to baby before birth to lower the risk of severe RSV infection and hospitalisation. Baby can still catch RSV after birth of course, but the aim is usually to make the illness less severe. The downside for many parents is really the cost since it’s currently mostly out of pocket 😅
I haven't done the RSV vaccine myself yet, but I've heard from a few mums that their babies were fine after it. The thing is, if KKH recommended it, it's probably worth considering since they see what's going around, but $300 cash is no joke when it's not covered by Medisave. You could always ask the doctor what the actual risk is for your baby's situation, or even check with your polyclinic if they offer it at a lower cost, just to compare your options before deciding.