Fix them and reuse
You might find replacement nozzles at Home Depot or similar.
But, they're pretty easy to fix and reuse. Just get a small glass jar, put some lacquer thinner in it and soak the offending nozzle in the lacquer thinner for a few minutes.
Then blow the nozzle out with some shop air and whalla - new nozzle!
I've also found the main clog problem isn't always in the little spray hole. If you look closely, the stem of the nozzle assembly has a very small slot in the side of it. That slot must remain clear or the nozzle won't work. I've even opened up the slot on some nozzles very carefully with an Xacto knife so it won't clog so easily again. That also influences how the nozzle sprays - the amount of paint delivered.
Finally, when you run a spray can dry, save the nozzle. You'll build up a good enough collection of them for future situations. Not all of these nozzles have the same geometry, orifice design, etc so you'll gain a variety of spray patterns too.