Gregdude:
These previously $30 tubes are now being offered @ $140+++/each.
Aside from backup sets the OP will also require suitable backup tube sockets due to to the operating "heat" of the tubes.
I offered a link to what appeared to be a reasonable price from a tube dealer in Germany and you offered - what?
I'm leaving Teo alone as my blood pressure is exceedingly high today, though I do wonder what his AA moniker is as it seems that he's toadally into Rod.
DeKay