Okay, here are the problems with what you're saying:
1. I was joking. You all need to learn to chill out.
2. There was no way that OKC could have offered Harden 80 million like Houston. It was physically impossible because Oklahoma City already gave their five-year "superstar" contract to Westbrook. However, and this is a big however, Harden wasn't asking OKC for 80 million. He wanted to stay there and knew the most they could give him was a four-year max deal.
3. The money Harden's side was demanding was reportedly about six or seven million more than Presti was offering. Not six or seven per year. Six or seven over the life of the contract.
4. The team very easily could have waited until next summer, amnestied Perkins (who sucks, by the way) and his dead weight eight million dollar contract, and then inked Harden to a four-year max deal.
They traded Harden because they were utterly unwilling to give him that extra 1.5 million a year despite the fact that he was 23 years old and already one of the best thirty players in the NBA. That's absurd. You don't trade a you star player when you don't even know what his ceiling is. You don't trade the glue guy on a team that was three wins shy of winning the Finals less than six months earlier. You just don't. While I don't think Presti should be fired (seriously, guy, take a joke), he made a huge mistake in picking the corpse of Kendrick Perkins (who had a single digit PER last year, mind you) over a 23-year-old star with a ludicrously bright future who everyone on the team loved.
And those are, by the way, the types of moves that get GMs fired. Not immediately, but in the future.