For many years glass and china ruled in the "smalls" category of the antiques and collectibles business. Many people feel that that is no longer true, they complain about the poor sales of glassware and how its just not worth toting around anymore. Unfortunately for them its not a matter of glassware not selling, its a matter of the sellers did not keep up with the times.
Dealers, appraisers and collectors sometimes forget that the antiques and collectibles business is in fact a business. A business that like any other is effected by supply and demand. Take a common collectible glass like Fostoria's American Pattern. Fostoria American has been around since the 1930's. The problem with the value in today's market is simple, Supply and Demand. The largest collectors from the last 50 years are now approaching their "golden years" and are divesting themselves of their collections. There are still avid collectors of the glassware but the availability of American glass has outpaced the demand. When 500 people are selling and 400 are buying the prices will drop.
Conversely, when demand is high and supply is low the exact opposite is true. Anyone with a boxful of scrap sterling silver will tell you that they could not believe how much they received for their metal. In recent month's investors have created so much excess demand for precious metals that prices have skyrocketed. Two years ago you could buy scrap silver for $5-7 per troy ounce, today it is over $30 per ounce.