At the moment I pay $30/t, as of July this goes up to $105/t....

At the moment I pay $30/t, as of July this goes up to $105/t. Every morning there are a dozen (give or take) rubbish trucks lined up out the front with interstate plates. So every morning you're looking at 400m3 approx of NSW rubbish being dumped in QLD. I think NSW dumps are already around $120/t at the moment, been a while since I saw figures. So they're effectively saving $90/t on tip fees, depends what they're carting but a 40m3 truck probably has 30-35t average. 
Work on 30t for argument sake, cost is $900 to tip + $100/hr for truck and driver (might even have negotiated rates in these cases?) At approx 24hrs $2400, total dump $3300.
dump local: 30t x $120/t + 2 hrs round trip $3800.
Save $500.
Worth it? Not sure, depends on the corporate structure, who owns the trucks, how often are they dumping, etc. 
if you had 1 truck per week $25k/yr, 5 trucks a week $125k/yr, all 10 trucks are yours every day $1.25m/yr.
For NSW waste industry 50 loads a week diverted from QLD is an extra $9M/yr revenue for local dumps. 
If you've got the Monopoly, good chance this rubbish is going to your dump. 
All napkin calculations of course, and I don't know the origin of these trucks, quantity of trucks, all speculation, Yada Yada, not financial advice.  
They also did an episode on ABC's war on waste on this exact problem, so you too can see the impact of you are interested. 
IMO things are up from here, December financial report will be the first indication of the impact I would imagine.
Directors took the opportunity to buy more as soon as they could too, they know SP is crazy here.