I dunno whether you need 700K to get 5th - Teams like Aussie and Yoda were running more like 600K, and managed to get second.
So if we go down to 600K wage budget, there goes $1.1m of the difference.
A team that finishes 8th gets less income (I assume) than one that finishes 5th. Lets say that's around 50K a week (it may be more, or less, I have no idea).
So there goes 550K of that.
Then the following season in D2, teams that get relegated get hit pretty heavily in crowd numbers no? So in order to repromote, a team would have to run a wage budget at least at the breakeven point. Maybe beyond. While the team in the ABBL is probably earning around 150K a week if they are at 600K wages.
So that's another $1.65m of difference gone.
Plus the tanking team probably exits the cup earlier than a team going for 5th. That could be another 100-200K or difference gone.
Taking all that into account, and the team going for 5th comes out ahead
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.