From what I say here, these were from the ‘net reports of the time of GB3’s rumors. The GB3 budget was estimated to go up to $120 mil. Keep in mind this was when Dan Ackroyd had an initial draft and the projected budget came off that, and possibly lead into a cliffhanger for a 4rth film. Columbia/Sony supposedly balked at this and wanted Dan to cut out any unimportant scenes, hence the need to do another draft.
But the other thing that caused GB3's budget and negotiation problems was the pricetag that the actors/director wanted. Ramis, Ackroyd, Murray, Reitman asked for an amount (price + gross %, rumors up to 40% of the gross) that was way too high for Columbia to make the film with any financial returns for the studio . Ramis has always stated that the negotiations was the key reason for GB3 not coming. Then rumors that Murray changed his mind but still wanted money to not be in it.
The thing is the first two GB films costed around $30-$34 to make back then. By todays standards, that probably would have at least doubled. And also I always heard back in ‘89 after GB2 ended its theatrical run, it was the mockery gossip by the entertainment press that Columbia didn’t make much of a cent from the GB2's gross. That most of the earnings went back to the actors/talent. It was the mockery joke among hollywood that a studio couldn't make money from its own production. Gotta wonder if this is true.
What does Murray get for a film? I believe I saw it on the IMDB website or ET weekly mag, that he makes up to $9 mil a pic.