Leaving aside other variables (and assuming the numbers are solid - for all I know a man in the street could make these numbers up and mentioned them at a football function), this is very important.
13500 x $18 x 13 home games = $3,159,000.
So assuming all other spending stays the same, they only need to hit $8.3 million and the only change is the TV distribution, we go from needing a crowd of 13,500 to 10,936.
That makes a huge difference to the economics of the league last year's numbers, and a break-even of 13,500 yields the following:
A break even of 10,936 looks very different:
The weakness here is that not every club has the same cost base. We run pretty lean (I gather) but others may run leaner. Others spend more either by choice or necessity.
We won't earn as much off-field as the big city clubs either, so it's pretty hard to offer a cast-iron guide, so bearing these pretty massive (and knowingly flawed) assumptions of equal cost and revenue bases in mind, you can take these illustrative figures with an appropriately-sized grain of salt.