What a deal I got

Ok, this is the scenario.
Our friend Karen's computer died and I was charged with picking up a new one. I went to Costco last night and picked one out for $899 which she approved. Went back today to buy and the price was no longer there. I asked an employee to please check the price before I bought. He says since it was the last 2 in stock, he'll ask the manager for a markdown.
Didn't see $540 coming. 
What a deal she got.