Based on KKH’s latest estimates, B1 c-section (4D3N) is around $10.7k total before Medisave. Medisave covers about $5.9k, so out of pocket roughly $4-5k. Deposit is around $2k+ at admission - they’ll give you exact amount at your financial counselling session (usually around 36-38 weeks).
On the husband in OT question, yes for private route husbands are generally allowed in. Subsidised route usually don’t allow. So if having hubby there is important to you, that’s another reason to go private. Do check with KKH directly though as policies can change!