Technically a Web Find but a relatively off topic one so I'm putting it here.
Dumet wire is pretty easy to find on Ebay, but only in large quantities costing $100 or more. Recently I was looking through the United Nuclear site (they have a bunch of cool stuff), and found that they sell 10ft lengths of Dumet for $15. It is .35mm diameter which is approximately 22 AWG. IDK if anyone else is interested in making their own discharge tubes/neon sign electrodes, but if you are this is pretty useful stuff obviously.
https://unitednuclear.com/electrical-devices-c-27_37/dumet-wire-p-1332.html