I get the impression that it is implied that you should offer exactly the same amount of space in a vault as much you use (upload and use the safe network)
but doesnt the data I am uploading get in 5-10 computers? so the data I upload is 5 times my data so I should have a 5 times my data vault?
Not really, the safecoin currency means you can buy resources (space). If you farm you will get these for doing that, it will not be far X bytes get a safecoin to store X Bytes though.
The farming algorithm isn’t set in stone yet, but it is thought that you should have a vault around the size of the network average vault size. This hopefully maintains a high degree of decentralization in data storage.
If your goal would be to earn back whatever safecoin your spent for storage, then over what timeframe? I don’t think at this time there is a good estimate of how long this would take.
No that is likely to be very incorrect. You will pay safecoin you buy or farm to upload. The farming algorithm will ensure this is the cheapest storage that people (farmers) are willing to allow. The network will “find” the cheapest storage automatically through the farming algorithm.