I just bought "On the edge" a book about Commodore business machines.
Look at the product number.
Coincidence? or the data entry guy is a retro-nerd sending a message?
Nope, I had placed an order for the old edition for 20 USD.
They told me they didn't have stock.
Now it's at 100+ USD
I tried to buy it on its editor page from which I took the screenshot. I placed the order and 10 minutes later they cancelled it because it was sold out.