I monitor sales and keep detailed stats of final values of chips sold on eBay, and the latest trends:

LE chips, as a whole are WAY down.

Truly scarce Vegas/Nevada/AC are up.

Sniping has become the norm for many serious bidders.

When I want a chip, I basically take an average of the sales of that particular chip and set my roof at about 80% of that price (unless, of course, I GOTTA HAVE IT!!!!)and that is where I set my snipe. Up until last year, I had good success with this, and weekly, I'd pick up a few chips. Recently, I have not won a single chip using this method. Not one. I collect old Vegas, and across the board, in the past 4-6 months, final sale values are up.