I began by looking online - and I found a nice sofa bed for $499:
So, we went to the store. The same sofa bed was on the display floor:
As you can see, the price is clearly marked as $499.
However, when I tried to actually buy it, Iriana, the sales assistant, said that it doesn't cost $499. It costs $549. Why? Well, they don't have it in stock, which means they have to order it... and they won't let you pick it up at the store when it gets in. Instead, they will only deliver it to your house. That costs $50, so it's really $549.
Of course, I said "uh, but that sign says $499, so can I just pay $499? I really want to buy it." She said no. I asked for a supervisor, she said she was the supervisor, so I smiled, said thank you, and went downstairs to the customer service desk.
The helpful woman there - she had a Nahuatl name - called someone upstairs and they too explained that, well, if you want that sofa bed, you can't actually buy it for the marked price. It will cost you $549 to buy it, regardless of what their Web site or display model say.
We didn't buy it.