Time spent researching an item before you sell it can be a good investment. In 2007, one eBay seller was probably happy to attract a winning bid of $300 for a single bottle of vintage beer. But imagine how that seller felt when the buyer - who knew exactly how desirable the 1852 beer actually was - turned around and sold the same bottle for $503,000.

When it comes to selling online, knowledge is power. An antiques and collectibles marketplace called WorthPoint not only offers a place to buy and sell, but also provides information so sellers can write accurate descriptions with market prices. And that, says its CEO Will Seippel, enables sellers to get the highest possible value for their merchandise.

"To me, it's the data that helps educate a buyer or seller," says Seippel. "You can talk all you want about marketing and finding the right place to sell something, but you have to go back to a more fundamental question: doing research so you can understand what it is you are trying to sell and what its true value is."

A newly developed version of the WorthPoint site gives buyers and sellers plenty of ways to gather this sort of information. Right now, they have access to the half million items in WorthPoint's database. In March, WorthPoint will add the database of past descriptions and sales on GoAntiques, a live auction-style marketplace acquired by WorthPoint in 2008. And after that, the site will add a full one-third of eBay's sales records for collectibles, purchased from Terapeak and "spidered" in as sales are made. The result: the "Worthipedia," a database of 15 million items.

On top of that, buyers and sellers have the ability to "friend" one another in the same way Facebook users do. A group of experts called Worthologists are available to answer questions about specific types of collectibles. And people whose business it is to sell antiques and collectibles, such as dealers, have the option to create a home page on the site where they can, for example, publish a calendar of upcoming sales and other events.

Seippel, 52, who lives in Atlanta, is a collectibles dealer in his own right. He started out as a member of the New England Antique Dealers Association with his own brick-and-mortar antique store. He has no nostalgia for those days, however. "I hated people coming in and taking stuff apart, trying to find little faults with them so they could get a lower price," he says. "I loved the electronic marketplace as soon as I found it. To me, this is a huge amount of fun."

His five children also collect; his oldest son likes Pez dispensers in particular. Seippel is an eBay PowerSeller, and he estimates he has sold more than 10,000 items in that marketplace. Collecting rare coins is his particular passion, so he has been actively involved on both sides of the sale with understanding his merchandise thoroughly and accurately estimating its value. And he knows his way around a database. He was involved in managing PC products and software product lines as well as other technology for Digital Equipment Corporation, and later helped United Airlines turn around their data-intensive reservation system. He has also managed some of the world's largest database technology building oil drilling earth models with some of the world's most data-intensive models at Halliburton.

He estimates traffic on WorthPoint has grown by as much as 4 percent per day since purchasing GoAntiques. While GoAntiques was primarily oriented toward professional antiques dealers, WorthPoint puts out a special welcome mat for individual buyers and sellers. You can buy a membership for as little as $3.95 per month that will allow you to place up to five items for sale at a time.

But there are plenty of marketplaces around where you can sell merchandise. WorthPoint is special because it provides so much information in such a user-friendly format. The database is easily searchable, and there are numerous ways to quickly pick the brains of experts and other members of the user community. "WorthPoint's first goal is to educate people," says Seippel. Being able to find merchandise easily is another, he says; accordingly, WorthPoint has spent time developing a "taxonomy" in which objects are logically organized.

WorthPoint is still a work in progress. There are plans to assemble a huge searchable database. Another improvement on the horizon is providing prospective sellers with a "virtual room" where they can learn exactly what an object is and identify auction houses that might be interested in selling it.

Where others see a gloom-and-doom economy, Seippel anticipates a bright future. "Between WorthPoint and GoAntiques, we attract 1.4 million unique visitors per month, which is pretty good for a company that's been around for two years," he says. "Some people say collecting is dead, but I don't think so. I think it's a great time to be in business. Data is so important to people. For consumers in this economy, getting the right price is more important than ever."