There are other solutions for figuring out how much items are worth on the AH, notably Auctioneer. However, where Auctioneer works by having you periodically park your character at the AH and scan all active auctions, WoWEcon works by spying on your mail. Every time you get a buy or sell notice from the AH in your mail, WoWEcon records the price, and transmits that data back up to the WoWEcon servers, where it all gets crunched together with all the other WoWEcon users' data and sent back to you the next day. Some people, myself included, believe that by going off of what items sell for, as opposed to what they're listed for, WoWEcon gives more accurate and realistic pricing data. It's also appealing to me that I don't have to bother doing scans all the time, I just need to take a few seconds every day to let the launcher download data. On the other hand, there is a bit of sample bias at play here: only transactions that have a WoWEcon user at one or both ends are included in the data. That's probably negligible, but you never know.
A word on WoWEcon's executable component: the WoW community is rightly very skeptical of third-party programs that are run in association with WoW. It's always possible that such a program may contain a keylogger, trojan, virus, or other bit of nasty code that could seriously compromise your account's security, and in general I don't recommend using any non-Blizzard programs to modify your WoW stuff. However, WoWEcon has been around for quite some time and is very reputable. There was a virus scare about it a few weeks ago, which prompted the site to pull down its .exe downloads and check them for malicious code; it was concluded that the scare was only a scare, and the launcher had never contained malware. Use at your own risk, of course, but in my opinion, this is one case where the risk is minimal. It is also true that the executable quits before opening WoW, though it does sometimes seem to re-open (presumably to transfer the price list).
By the way, there is a "premium" version of WoWEcon, which costs $4 a month (less for multi-month packages) and gives you access to additional features, like price alerts (via email or sms), sales reports, and a whole lot of charts. I haven't ponied up for it, since I don't think I spend enough time on the AH to justify the cost, but if any of you have, let me know how it is.
Download from the wowecon.com
Previously on AddOn Spotlight