Are these sentences natural? November 21

[Musicgold]

Hi,

Are the following sentences natural to a native ear?

1. They knew that those business were not going to work and they would be able to buy them back on the cheap.

2. I will let you know once he calls me back / has called me back.

3. Did you get this cup made for you? (I was asking a person about the custom cup they had in their hand)

Thanks,
MG.

[Dozy]

All OK except #1 should be "businesses".