Originally Posted by
Dark Mits
I have taken this one step further...
As long as I do not need Extra and Material Storage "right" when they expire, I can keep them closed/locked/read-only until I desperately need them. This is usually about 10-15 days after they expire, depending on what campaigns exist at the moment. So basically I can get 1 month for both for 400SG and have it run for 40 days, which is 10SG per day. At the same time, refreshing the 3month versions when they expire means a cost of almost 1SG; the "net" benefit is 60SG per 3 months.
Though for the above to work, I have to guarantee that I will not forget to stock Extra and Material Storage right before they expire to empty room in the other storages. Also, the above doesn't work on extreme hoarders.