Well, below is a link to a pair at EBAY for 106.78 each, using the "buy it now" option. You might bid and win at much less than that.
I bought a quad of these tubes from a guy in Germany about a month ago on EBAY for $56.00 each. Quite a bit less than your $350.00 each quote. I think you need to shop a bit before paying that much.
Ebay Siemens
I bought a quad of these tubes from a guy in Germany about a month ago on EBAY for $56.00 each. Quite a bit less than your $350.00 each quote. I think you need to shop a bit before paying that much.
Ebay Siemens