I have won a couple of nice things for 99 cents, and to make me feel even worse, they cost more to ship than the seller charged. They actually lost money by selling. I felt bad, but a deal is a deal.
You probably bought a cylinder head for a YZF750 that I listed eight or nine years ago

.
A friend was parting out his Yamaha and I offered to list his items on eBay. I listed half a dozen engine parts (heads, cyl block, carbs and such) and set it up (so I thought) to
add $5.00 for packing materials and started the auction @ 0.99 cents.
When the auction ended the buyer immediately paid the $5.99 and I sat at the computer screen dumbfounded

. I thought about contacting the buyer and telling him about my SNAFU, but my wife told me to **** it up and learn from my experience.
Of course, it was the heaviest and
only item to sell. To add insult, the buyer lived in California and we lived in Spain so the shipping was fairly high.
Oh well, at least two people made out: The buyer got a smoking deal on a cylinder head and the Yamaha owner got $5.99 for something he was gonna throw in the dumpster anyway.