Buying tubes at Ebay?

How one can be sure with tubes from Ebay? For example, would it be OK to join a bid like this:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=9731990455&fromMakeTrack=true

Anyone had experiences with buying valves on Ebay, good or bad?

 

I've bought new, used, and nos valves off ebay and they've all been OK so far, but there are few guarantees....you pay your money, you take your chances!

 

Earlier this year I had a big buying spree on Ebay for valves, (ECC83/12AX7/5751 types). Most have been great. The odd couple or so that have been microphonic I sold on for a profit. Like the man says, you pays your money and takes a chance. As long as it doesn't get stupid expensive, go for it and see what happens, but remember: it's a global car boot sale!