Function
People value antique vases for several reasons. Collectors value them for their rarity and the history that they symbolize. Dealers value them for the potential profits that they may bring in. The "average Joe" on the street may not be that interested in antique vases, period, but also could value them for their beauty.
Significance
Several things determine the value of an antique vase. The type of service that the vase performed is important. For example, while a flower vase is fairly easy to come by, a small, opalescent "fan and feather" ladies' spittoon like the one seen below might be worth hundreds of dollars to a collector because it is rarer than regular vases. The age of the vase is also important, as is the manufacturer. If a vase was made by a manufacturer that is still around today and mass-producing glassware -- a department store, for example -- then it will likely be worth less than a vase that was either handmade or produced in limited quantities by a manufacturer who is no longer in business.
Features
A valuable antique vase will have several defining features that will let you know that it is potentially worth something. It will be in whole condition. Broken and repaired vases simply are not as valuable. It will also have a clear mark that indicates the maker or manufacturer. Without this mark it is impossible to prove who made the vase--although many dealers will speculate if they think it will convince you to buy. Truly valuable vases will also have a year or other defining characteristic that makes them easy to identify and date.
Considerations
When you are considering buying or selling an antique vase, be sure to get an appraisal even if you are certain that you know exactly what you are purchasing. Particularly if you view the piece as an investment, you need to be sure that there is some type of market out there for it, or you may not ever recoup your money. Your appraiser should be an independent agent and certified in antique vase appraisals.
Misconceptions
Many people think that the older a vase is, the more valuable it will be. However, age alone does not determine value. Popularity among collectors also plays a major role, as does rarity. For example, lady head vases, Depression-era glassware and Oriental vases are all extremely popular with collectors. However, lady head vases are relatively inexpensive because they are sturdy and were manufactured in great quantities. Depression-era glassware is more valuable because although there was a lot made, it is fairly fragile and it can be difficult to find a piece intact. Oriental vases are the most expensive because they are very rare and were handmade, so each one is different. Lady head vases may be purchased for a few dollars, while legitimate Oriental vases may cost thousands or even tens of thousands.
Warning
Never buy an antique vase sight unseen unless you have a clearly written return policy that you know will enable you to return the vase if you are not happy with it. Using electronic photo alteration techniques, unscrupulous dealers can make ordinary vases appear to be rare items. Always make sure that you will be able to get a full refund if the item you are purchasing is not actually what it is alleged to be.