The answer is a bit complicated, and not necessarily good news for those who buy the wines to drink them.
Starting this past fall, several things started to move dramatically. It started with Giacosa- in one prominent fall sale about half the lots went unsold and the ones that did sell stayed near or at reserve. Rousseau was next, and in the past 90 days it is happening with DRC. The drops have been relatively dramatic and have had some impact on the lower end of the range for those wineries. Like you Mark, I got out of the Rousseau game a long time ago, but in the past couple of months I have purchased several cases of recent vintage Rousseau GC, Ruchottes, Charmes and Clos de la Roche at very nice prices compared to how things were 6-12 months ago- and I plan to drink them. But I have not touched the Big 3- those are still beyond what I am willing to pay. Some of the cases I got at auction, and some from retailers who had been trying to get really high prices on release stock and had been sitting on the wines for quite a long time (in proper storage of course.)
A lot of it is a question of supply. Last spring prices got really insane, and so this fall we have been treated at auction to an embarrassing quantity of many top wines that are usually quite rare- even in an auction setting. It is a perfect demonstration of the fact there is a supply of wine at the very top which is being frequently traded at auction and in private sales in much the same manner as contemporary art actually.
But that world is very separate from our own. There are still a great many merchants around the world who take in these top wines at release and sell them at a normal markup. There are still waiting lists years long in many cases to get access to top burgundies in that manner. And the DRC of course has their private list which means many of the biggest collectors buy at prices that give them no reason to even look at the secondary marketplace.
So while the speculation market is in a bit of a lull, it is business as usual in the more traditional marketplace with normal retail markups, and I really do believe that if the secondary market evaporated tomorrow there would still be enough demand in more traditional venues at those lower prices to fully absorb the impact, and still there would be customers on waiting lists.
For practical purposes, I think 2017 could be a bit disruptive- generally very good scores from BH and JG even if the vintage itself does not have a 5 star perception, and also very good supplies for the first time in a while. That is going to put downward pressure on everything to some extent.
But I am already hearing tales of massive price increases for 2018- so we will be right back in it before too long.
Current buying strategy- go for the less-famed bottlings from the best houses in good to very good vintages at auction. 2014s are a particularly good target right now. It is a rare chance to get things at acceptable prices that many of us have avoided for a long time even though we want them in our cellars. But it is a temporary thing. There are just too many collectors and too few bottles of Burgundy out there these days for a substantial long-term rollback in pricing.
JMHO.