There are huge leftovers of radio and indicator tubes, including nixie tubes, from Soviet era. After the dissolution of USSR, many factories stopped working altogether and the production stock was stolen by former workers. Now these radio components are sold on black markets by people, myself included You can buy nixie tubes at eBay at moderate prices. For example, consider my eBay item: that has been removed as advertising, which is against the rules here. These are some rare green indicator lamps ITS1A.