What are used tubes worth ?


My ARC VT100 blew one output tube (the filament opened) so I replaced the entire octet.
So, I have seven 6550 output tubes that work fine, and have probably 800 to 1000 hours on them. They are the original tubes that came with the amp.
Any idea what they might be worth ?
Thanks.
mabonn
It is a Mk II amplifier. The hours do sound low. I used the amp only a few hours per month. What can I say, I was busy with career and raising 3 kids, so I had very little time to listen to it. Anyway, I sold the amp, but still have these tubes.
Agree that they are not worth much as most want matched sets, but since you have no use for them, they are at least worth something. Price in part would be based on their normal life expectancy...