If I researched the entrance fee to Petra, and the cost of travel from Amman to Petra, ahead of time, I may not have gone at all.
Once the price reached 50 JD, they realized the discouragement had failed, so they added this new 90 JD fee, but never decreased the 50 JD amount.
I will say, if I would have done my research ahead of time, and knew that it would cost an additional $100 per person to see these sites, I may not have stopped over in Jordan.
With how I was feeling two weeks before our arrival in Jordan, when we adjusted our travel plans and decided to go home early, if I had known it would cost $200, just to see these two sites (plus $200 for transport), we probably would have connected straight through and skipped it all together.