So, now with the recent rebalancing changes made on beta, we know that;
a) There should be enough added footballs to all the quests to complete a Lv10 building w/out diamonds...
Of course, this still assumes that you complete the entire quest line & get the daily log-in footballs. And that you're not the doofus who's just blindly clicking 'randumb' players, and will make some use of the handy chart on the wiki to always pick the best balls per yardage players to help increase your odds further!
b) Upgrades will NOT be made into daily specials this year, as Inno has decided that this building is far too powerful to become readily available with only a handful of diamonds.
If you want a second Collossus, it's going to cost you roughly 34k-35k diamonds per.
(note: I'm sure there's a few whales out there with more $$$ than sense who will break open their wallets for an extra Lv10 or three!
)
Really happy to see that Inno have listened to the complaints and at least made the Lv10 achievable by doing the full quest line + daily log-ins, and also being at least a little intelligent with the mini-game.