On my most recent sets with Ron Hep...
5 votes gets you the full original size set
10 votes gets you an additional 5 unpublished photos from the set, as well as the original set.
15 votes gets you 10 additional photos on top of the full original set.
And 30 votes gets you the full set with 10 unpublished photos, and a full original size set of an upcoming unpublished set"