Cruise control switch - should be able to get a brand new one for about $70-$100. Very likely to be able to get one from a different Toyota - as they don't really change the design that much - double check a cross-reference (dealership or parts store will be able to check this). That case, might be able to get one from an earlier Toyota for considerably less - some at Rockauto are going for around $30-$35. Before you start shelling out any money - see if the dealership will cover this under warranty. Worth asking.
Part itself is not bad to change, assuming that Toyota cruise control setups didn't undergo a quantum leap in technology change between generations. First disconnect the negative battery terminal as you'll be playing close to the airbag assembly later (note alarm systems will not like this, make sure you have the appropriate way to disarm/reset them later). You have to remove the steering wheel pad (airbag portion) - usually there are screws on the left and right sides of the steering wheel (likely need to use a torx or star bit to remove them). Pad just pops up, exposing the two screws holding the cruise control switch (likely to be torx screw heads) and the wiring harness for the switch. Remove replace, reattach the pad - and you are good to go. 30 minutes, tops, to do this kind of repair.