West Coast fans are overestimating the gap btwn what they'll offer and what Sydney/Freo will. I can see West Coast's offer being 10-20% higher than Freo's/Sydney's, and that could be enough to be decisive. But some West Coast fans are peddling the idea that they're gonna damn near double everyone else's offer, which is nonsense.
For one thing as you said, for a player of that quality you make the room. But for another, teams don't make offers that are just completely out of whack with market value just because they can afford it for that 1 player. Sure if West Coast offer 2 mil+ per season it might be "too good to pass up" money. But it'd also be "too high not to obliterate your pay standards" money. Suddenly every West Coast player who's remotely good has their manager up their demands coz they're comparing their output to Chad's and want their pay to be proportionate. Lord knows what Harley alone would demand on his next deal.
1st year may well be double. Then remaining years 10 - 20% higher.
Sign on bonus yr 1 while the cap space is available.
Not difficult to turn his head and seriously outbid both Swans and Freo in year 1 of any deal.
It how the salary cap works in favour of clubs not contending.