Make an Informed Decision when buying glass.  Whether for investment or because it is the pattern you collect, the condition of the glass is very important and affects its value.  Before bidding, ask the seller specific questions about the item's condition.  Never assume a seller's definition of perfect is your definition!

eBay provides a good reference on Typical Problems associated with glass defects.

Here are questions I always ask a seller before bidding:

1.  Are there any flakes, chips, flea bites, or nicks?

Ask about all four because it leaves no chip unaccounted!  Sometimes things are overlooked by the seller when the glass is first examined.  Sometimes the damage occurs after the seller takes pictures.  Nevertheless, this question should make the seller re-examine the piece to be sure there is no damage.  Several times I have had someone find a flaw after I've asked this question.

2.  Are there any rust stains, water stains or spots, or cloudiness?

Rust stains may come out of glassware but water spots and cloudiness are most likely permanent.  This type of damage comes from washing glassware in dishwashers, leaving water in or on the glass for extended periods, and even from humidity.  (Humidity stains sometimes look iridescent.)  The glass is considered sick glass.  The severity of the cloudiness determines how much of the value is affected.  You want your glass to sparkle!!

3.  Are there any cracks or repairs?

Cracks have the greatest impact on value because the integrity of the piece is at jeopardy.  I have bought only one piece of glassware knowing it was cracked.  My purchase was an informed decision with no regrets because I am not going to resale the item, the price was very low, it is a rare piece, and the crack is difficult to see when displayed.

4.  Are there any major scratches?

Light scratches should be expected in old glass - such as utensil marks on dishes and scuffing on the base from sitting.  However, you do not want the scratches to be distracting from the beauty of the glass.

Also, a scratch is not the same as a strawmark.  The latter is considered a manufacturing flaw and common among pressed pieces.  A scratch feels like an indent into the glass; a strawmark is usually raised from the surface (like it was embossed).

A good seller will mention all problems and provide photos of the flaws.  But even if the description says perfect condition, ask what the seller means by that phrase.  Also, a seller who rarely sells a piece of glass may not know to look for all the things mentioned above.  It is better to ask questions beforehand than to have regrets later.

Keep the emails back and forth between you and the seller until you have received the item and examined it for yourself.  If you find a flaw that was not disclosed, having that email goes a long way towards accountability with the seller and is leverage in your favor.