Tero: Antique Electronic Supply 6221 South Maple Avenue Tempe, Arizona 85283 USA (602) 820-5411 (PHONE) (602) 820-4643 (FAX) Has 810's for US $107.20 each, Soviet 811A's for $18.00, Soviet 833A's for $130.00. Those prices seem pretty high to me, but they are below your threshold. You can probably do better, but not sure where as I'm not in the market for any now. Ed Phillips