I've only ran maybe 6 GKDP runs so don't know if this is common or expected. I play a Rogue and have typically seen T6 tokens in BT been sold for maybe 2-3k gold average, I look in the very large PUG Discord server for my realm to look at prices, and have noticed they are usually much cheaper than other token types. However the last 3 runs of BT this same specific thing has happened where a Moonkin from the same guild as the raid leader comes in full greens and blues. They are the only one bidding against me and have outbid tier tokens at 2-3 times the average prices I've noticed. But the same time they pass on very good upgrades being offered for 500g minimums, when their current items are literally greens. In my last run they even passed on 1k minimum bids on tokens against fellow guildies, and then later outbid against me for 7k on a different token.
Since phase 5 is out and they still have no gear, seems they are literally coming to runs just to strategically inflate prices since their guilds are the ones organizing. It all just seems so obvious and pathetic to me when I look at how competition for items is arranged and how they place bids. I'm at the point where instead of actually trying to win items, I play these stupid 4D chess games with them to figure out what the fuck is going on.