Seven is not going to keep all the games for themselves if they do get the rights. However, if they do get them, I could see 7 keeping the Sunday doubleheader, Origin and maybe a couple other games like tests and City vs. Country and onselling the rest.
In this scenario, 7 would:
-Have a massive Sunday news lead-in with a northern/southern split of NRL and AFL.
-Be guaranteed of winning 3 weeks by having Origin and denying that advantage to any other network.
-Denying 9 and 10 exclusive NRL rights and the potential of rebuilding network share by having exclusive NRL rights.
-Soldifying its position as Australia's number 1 network
-Denying Foxtel's chance of increasing their market share in NSW/Queensland
-Making a profit on resale.
Even if Seven does not win the rights, they will still break Nine's and Fox's First and Last rights and force the other networks to pay overs. A crucial factor between a low figure (below $1b) and a high figure is Seven's involvement as they will step on everyone's toes.