I have to admit I didn’t know much about the phenomenon called eBay, the hugely popular online auction Web site, until the boxes started arriving at my house a couple of years ago.

There were a few heavy boxes, each addressed to my son, the budding car mechanic and computer technician. Inside one was a carburetor for a 1995 Saturn, I believe, and in another was a set of fancy yellow struts. Computer parts began showing up in the mail, too, which my son planned to use to juice up his PC. When I asked where all these things were coming from, my son patiently explained to me the boundless joys of eBay, where it would appear that everything in the world is available to the highest bidder.

“There’s probably nothing you can’t find on eBay,” he said. “And you can get stuff really cheap, too, if you look hard enough.”

I’ve yet to fully explore this high-tech auction house, there being nothing I desperately need to own or sell at the moment. But a couple of recent stories about the wonders of eBay suggest that not only is everything under the sun available for a price, there is no object so bizarre and tasteless that it cannot find someone who must own it.

There’s the now-famous sanctified grilled cheese sandwich, of course, whose original owner claimed to have seen the image of the Virgin Mary on its toasted surface a few years back. Rather than seek psychological counseling for her hallucinations, she decided instead to tap into that bottomless well of curious modern longing and put the half-eaten sandwich up for auction on eBay, where it fetched $28,000.

As proof that there are people who will buy anything, USA Today recently highlighted some of the strange odds and ends that have been sold for big bucks as celebrity ephemera at public auctions. If you thought selling an old cheese sandwich was crazy, and it surely is, consider this: Christie’s, the famous auction house, actually sold George Harrison’s half-eaten toast for an undisclosed sum, Justin Timberlake’s partially eaten French toast sold on eBay for more than $3,100 and an empty hair-color bottle used by the late Kurt Cobain went for $175.

Three tablespoons of water said to have touched the sneering lips of Elvis himself at a 1977 concert sold recently on eBay for $455. Not only that, but someone else eagerly paid thousands just to revel for a while in the company of the foam cup that held the water that the King sipped. The owner of the Elvis cup, who snatched it from the stage after a concert and put in the freezer, said he was inspired to sell the remaining 28-year-old water and auction off “guest appearances” by the cup after reading that a miraculous cheese sandwich had sold on eBay.

On eBay, the story said, I can even bid for a dozen or so pieces of chewing gum spit onto the ground by Britney Spears and hastily retrieved by her shameless worshippers. If I am willing to part with $99, I can get pre-chewed Britney gum that “still has saliva on it!!!” Last spring, a person tried to unload a half-eaten cough drop tossed in the trash by Arnold Schwarzenegger, and laced with “Schwarzenegger’s DNA,” but the eBay people turned the item down because of their rule against selling body parts. Jack Nicholson’s purportedly genuine baby teeth and adult molars fetched offers of nearly $10,000 at a British auction, however, and the unwashed socks worn by the singer Bryan Adams during a concert brought more than $1,000 on eBay.

Laugh if you want, but that $28,000 cheese sandwich just goes to show that it pays to watch what you eat.