This is how you attempt to buy things from a shopkeeper. There must be a shopkeeper present in your room in order for this to work. You can also buy things from a vending machine like this.

The numbers in brackets to the left (when seen in list)can be used in place of names when buying stuff. For example, if you saw this:

list These items are for sale: [1] a scroll of armor 8300 [2] a scroll of teleportation 8430

You could buy 2, or you could buy 2.scroll, both will be the scroll of teleportation.

buy waybread baker buy 3.sword 2.blacksmith buy ticket machine