I don't think you're wrong, but I think some context is missing. I was trying to sell at like 7k on Friday and people like Peepo were dumping at 8k. The rest of the day people had to dump closer to 8k, and then it was closer to 9k on Saturday as more payouts we sent out. The people paying that rate were almost entirely from our guild (or their item selling characters). The krono sellers are going to raise their prices when they see 80+ people trying to buy 500+ the current market value. I think things just steamrolled into price increase over the weekend, but the pricing didn't stabilize on Sunday when payouts stopped/decreased which is what was weird.
For context, the last time we dumped several million into the economy the price increased in a non-linear manner as well.