Bungee cord server ram management

I have been working on a bungee cord server for some time and when now its almost done i ask my self what ram needs each server.
On my bungee instance i has 10 plugins
http://prntscr.com/fknwn8
And i thinking to give 268 or 512 MB of ram.Wich is more normal for my server?
Skywars server with ~50 plugins - 2 or 4 ram
Survival ~70 plugins - 3- 4 ram
Lobby ~30 plugins - 1 -2 ram