segwit wallet has low fees really ?
The fees are pretty reasonable in general. Segwit addresses can potentially have a lower fee when compared to a similar legacy transaction. Segwit transactions has their weight counted differently which results in a "discount".
I guess this is why I confused things up.
So just to get things totally clear, services already support sending to P2SH addresses and that's why they all support sending to nested SegWit addresses?
Yup.
Every service and wallet that I'm aware of supports P2SH addresses, nested segwit or not. P2SH has been around for a long time.