David and I tend to go straight to eBay if we want to guesstimate the value of an item we're considering buying or selling at online auction. The volume of transactions on eBay makes it a good pricing indicator. (Be sure and search "completed items," and pay attention to whether the item actually sold!)

I decided to take a look at Auction Rover's Pricing Trend feature. (You must register to use the service.) I decided to find the value of Life Magazines from the 1950's, since I had some copies in my basement that I picked up at a real-life auction.

I went to http://www.auctionrover.com and clicked on "Bid" then "Price Trending." Then I clicked on "See what Items We Trend." I found Life Magazine under "Entertainment > Magazines > General"

Here are the results for Life Magazine Back Issues (1950s):

Manufacturer: Unknown
Item/Model: Life Magazine Back issues (1950s)
Average Price: $9.50 (All sites)
Average Number of Bids: 3.6 (All sites)

So what does "all sites" mean? Auction Rover searches 100+ sites (see the list at http://www.auctionrover.com/community/about/siteswesearch.asp). Though eBay is listed, a representative from AuctionRover told me that they do not search eBay auctions.

The Price History chart shows the average price from the last 30 days on all sites. The price ran along the $3.50 price range from April 4 through April 20th, shooting up to $6 by April 28th, and then falling to the $3 range around May 1st. (Since it never went higher than $6, I'm not sure how the average price is $9.50.) A second chart plots "volume" on all sites for the last 30 days.

In this case, I have an idea of the average price of Life Magazines from the 1950s - sort of. If the auctions included some particularly rare issues of Life Magazine, that might have skewed the results; what if my copies are not as collectible? Conversely, what if I have a particularly collectible issue that is worth more money?

I decided to go to eBay and do a search of completed auctions for Life Magazine. I entered "Life Magazine 195*" into the search box to limit it to copies from the 1950s. There were 546 items. Many had 0 bids. It was very useful scrolling down the issues to see how much the copies went for - clearly one important factor was the person on the cover. In this case, it seemed much more useful to use the eBay method of pricing.

A better use for the Auction Rover Price Trending feature is for specific products. Looking up "Ty Groovy the Bear Beanie Baby," I discovered that the average price for the past 30 days was $15.57. I could even compare "Ty Groovy the Bear Beanie Baby" with "Ty Halo II the Bear Beanie Baby," and could immediately see from the chart that Halo II the Bear got a better price at auction than Groovy the Bear. I know which one I would sell if I had both bears and was looking for bigger bucks from bidders. On the other hand, if it had simply listed Ty Beanie Babies, I don't think that would really tell me much.

AuctionRover.com has a limited selection of items that it tracks, but their public relations person told me they would add any item that a user requests.

Keep an eye on this feature from Auction Rover. And let me know how YOU "guesstimate" values on items you are considering buying or selling.