A stake per week ? I would say 1000 Stakenet but why would you want to get only 1 stake per week ? I would say that you can start slowly accumulate a masternode like I did as I think in 2 years it will worth x10 from initial price of 0.5$ which will make the masternode worth a lot. The team is working hard,  new dex coming, wallet looks amazing and xsn its on sale like all the rest of the coins from markets.

You can try tho a calculator to see exactly how much coins you will need but my guess its aprox 1000.