Note on this, before using the method, make sure the missions you are banking are actually cash paying missions. The dailies/weeklies in most DLCs are, but seasonal missions (like the current one) normally are not. I think these pay a little bit, but maybe not worth the effort. I'd stick with the normal DLC dailies/weeklies. I only mention it because the anniv event is on now so likely you'll run into this issue and I don't want to sour the idea.