Personally, I'm just not seeing the coins I want, in the grades I want Rob. I rather assumed that anyone with nicer pieces was either holding on to them, or perhaps selling privately. More likely the former.
Maybe we need another collection or two coming to the market, however when I consider Bob L's coins, or even Alan Morris', the proportion of coins I'd really like to own as opposed to the overall number, was still small. I guess that's the problem with a 'maturer' collection .. I'm on the hunt for either nicer coins or the scarcer ones. However whereas in the past it was finances (or lack or willingness to spend the necessary) that limited acquisitions, now it's simple lack of material.
And of course, that fuels the problem. Until I can upgrade what I have, I don't wish to part with any of my coins. In fact, if possible and unlike previously, I would prefer to add further to the collection without necessarily disposing of existing coins. But that means I have little to sell, ... assuming there are even specialist collectors in my field any more to buy what I have to offer..