Board Thread:Game Discussion/@comment-26829117-20180113114518/@comment-49.199.113.114-20180113115318

It will be different for everyone depending where they are. For me, it will cost 1000GC to upgrade and complete, I receive approx 250GC in rewards. So I see this as a 25% discount on upgrades.

The blog said 100% completion will allow completion of the 5 new series. Assuming 70GC reward per series = another 350GC without upgrades. So overall it will cost me 400GC for 1000GC of upgrades, essentially a 60% discount. That is worth it + I don't have to worry about unlocking any new Motorsport series first down the track.