Factory matched pair of Shuguang Treasure KT88-Z bought direct from Grant Fidelity in December 2011, I can provide proof of purchase if requested. Used for about 200, maybe 300, hours max in a single ended KT88 amp I was running on some high efficiency speakers. I am most likely overstating their use - they were barely used and are as new, and I was running another amp at the time as well so these saw very little use. I sold those speakers in early March.
On my calibrated Hickok 533A tester, these tested better than new at:
tube 1: 8500
tube 2: 8500
where 7000 is considered new. Of course, no shorts.
Save some money on a practically new pair, and save yourself the break in time (as these are probably just barely broken in). Perfectly match premium pair of the best sounding KT88 I have heard - and I have heard a lot of them!
Buy with confidence from a long standing audiogon member, and feel free to ask questions. Thanks for looking!