Normally I'd agree with people saying to save it, but you actually know of a couple things you want.
I'd say smartwatch (I'm eagerly awaiting the delivery of my Pebble), but knowing you're used to a triple monitor setup and now you're down one, maybe the monitor.
I have a couple friends who have smartwatches. They both really like them and feel as if they're useful.
Personally, I'd go with the watch.