Good-Find anything you want, use as a yardstick for pricing, entertainment factor (i.e. $1000 PCV valve)

Bad-stupid questions from people who may want to buy your item

Ugly-paypal thieves

Good-The face of the guy when he sees the credit card bill for the $1000 pcv valve that his wife bought him for Christmas!

Bad-The occasional overpriced postage fees

Ugly-Nigerian scammers

Good one Monty

Good; You clean out your barn and can actually get some decent cash for your stuff that normally would have set for decades or went to the land fill.
Bad; You get an auction 'right where you want it'. You have bid and set to bid again to finish it off. You think you just might get a deal. Then the seller takes the item off because of whatever reason......
Ugly; You either see the item(from bad above) was relisted or you hear about who bought it for a great deal.

Bad: Seller decides he isn't getting enough for his item and shill bids it up.

Ugly: You see the same item from the same seller re-listed two weeks later, trying it again.

good must be when you get the part free

Good: You buy video game cartridge from Goodwill for $0.95
Best: You list cartridge on Ebay and it sells for $200+

David

I've got one of those stories too. I had a shifter arm thrown in on a GTO deal. It wasn't a GTO arm, I knew that. So I whipped it on eBay a couple weeks ago and 'low and behold' it's a 68 442 shifter arm. Sold for over $300! That covers the good and ugly quite well.

And which one may this be so I can keep my eyes open?

Vulture Attack by K-Tel Vision for Atari 2600 (Rarity 9)
You would not believe what some of these games can fetch.
1 being common, 10 being rare as hens teeth:
Check out this site, you may actually have something of value:
http://www.atariage.com/software_search.html?SystemID=2600

Found a spacesaver for a Mopar at a scrapyard (holding the gate open ) asked the guy how much and he said take it, take as many as you like, I only have to get rid of them. (he sells parts based on the metal weight,god bless him ) Sold on Ebay for $200+

David