is it cheap storing on the AWS drive?

I think it is expensive.

S3 Standard Storage

First 50 TB / Month    $0.023 per GB

Next 450 TB / Month    $0.022 per GB

Over 500 TB / Month    $0.021 per GB

Your right it is, I have my own server that im going to be hosting on, with a HP SAS storage array, trouble is I dont see any option to tell UNA to save to it.

Do you mean like this with remote storage? 

https://una.io/page/view-discussion?id=2509 

I still can't figure it out, but I think I need to do NFS in Linux or something.