I recently replaced all the pedal pads on my B2910....ordered them from the dealer, and paid about $40 for all 6. If you have a parts manual for your tractor you can verify the P/N before you go to the dealer, and have them ordered. With all the possible combinations of tractors out there, it is unlikely that most dealers will have these in stock...or in sufficient quantity to replace them all at one time.
Mine were "Glued" on, so I had to cut them off, and scrape the excess rubber off the metal pads before installing the new ones. I didn't apply any glue to the new pads, but they fit snugly enough that I don't see any need to glue them.