Give me a few hours online, and I can ferret out the best deal for just about anything -- travel, electronics, whatever. But not long after I click on that confirmation link to finalize my purchase -- often with a no-refund stipulation as part of the bargain -- the euphoria of my penny-pinching achievement fades and a familiar feeling settles in.

I call it techno-doubt.

Could I have gotten a lower airfare to Scotland? Was that the best price I could find on my home-theater receiver? Might a different broker have better Matchbox Twenty tickets closer to the concert date?

I then spend the ensuing days or weeks doing the same online research to see if I really did get the best deal -- even while knowing that undoing the previous purchase would be impossible or impractical.

This modern problem of techno-doubt has become chronic enough that when I found nicely priced airfare and hotel for a family vacation to Washington, D.C., a few years ago, my wife let me buy the tickets in January for the June trip only if I promised in advance not to spend the next five months checking to see if I could have done better.

I know what you're thinking: OCD -- obsessive-compulsive disorder, a serious psychiatric problem for its sufferers and those close to them. No, that's not it at all. I don't have OCD.

And it's not buyer's remorse. I rarely wish I hadn't bought something (although the "deal" I got on refurbished Scooba and Roomba cleaning machines turned out to be a disaster).

It's just that Web technology makes it so easy to second-guess yourself.

For instance, finding the best airfare to Scotland largely involved monitoring the indispensable travel sites Kayak (www.kayak.com) and Expedia (www.expedia.com), along with several complementary online tools.

After the first visit to Kayak to check the rates for my dates, my search was automatically saved so that on return visits I just needed one click to run it again. And once I set up some preferences, I received an e-mail from Kayak whenever fares dropped below my chosen price point.

I ended up using credit-card rewards to get my airfare for a fixed number of points, so the going price didn't matter ultimately. I just had to pay taxes on the transaction.

Still, I couldn't resist checking airfares later just to see if my taxes would have been lower. The reason? That saved single-click search didn't go away once I had obtained my airfare; it taunted me with a come-hither "your recent searches" whenever I visited the site. And those regular e-mails about potential deals nagged at my techno-doubt until I opted out of that feature.

That's just one example, but it applies to just about anything you can buy online. Bargain-hunting sites such as Dealnews (www.dealnews.com) deliver news of price drops and money-saving virtual coupons, users in online forums share their tips and findings, and countless price-comparison sites relentlessly survey online retailers. They make it easy to find deals, but also often have time-saving features that make it hard to resist a post-purchase check -- just to be sure.

Here's the kicker: I almost never find a later deal substantial enough to justify my techno-doubt. But there have been a few times over the years when I wish I had waited a little longer to make that online purchase.

I call that Net regret.

Randy A. Salas • 612-673-4542