BUT, given these numbers, do people think that the prices are likely to come down over time, or will the popularity keep them up at current levels.

I don't think the price levels would go down even if the entire population was released to the public (exception might be the higher denotations). I think the "wow" factor of these Jetons will always keep them in demand. This would be the same with the MGM Jetons and Sands Jetons and Plaques.

The Sahara Plaques were just about the only "odd" Vegas item that dropped in value over the years but in just the last few years the value is starting to pick up for even the $20 and $100 plaques.