As I remembered, the tubes are in fact the Emission Labs 300B. They sell new here in the US for $505.00.
These tubes have very few hours on them. I seriously doubt they have more than 200 hours and in reality, probably half that amount. They are in the factory packaging and everything looks brand new, although I purchased them in 2006 or 07 (can't remember).
Honestly, just having looked at these beauties in the box and now I am not sure I want to sell them, but if I do, I'd be asking $400.00 for the pair.
Thanks,
gary