SetsulSettings? Especially the stream makes quite a difference. 320*240 at 15fps runs on a toaster, 1920*1080 at 60fps means i7/Xeon minimum.
Also if you're going for minimum there will be fluctuation.
Comanglia settings, 720p 30 fps for streaming. Also what about without streaming? Obviously that would make a big difference as you said, but how big in terms of price?