For me, it's a bunch of things that generally have to come together. There are exceptions.
It's mostly "does the item make sense, and does the sale make sense at the price. "
This warmup jacket was barely shown in the preview for a local antique auction. Literally hung on a door next to the staff jackets.
Supposedly Ernie Lombardis, with the claim he was a friend of the consigning family.
It's pretty big, reversible, and heavy cloth/leather. Sadly it also looks like a name has been cut off the back.
I don't know much of anything about 40's ML warmup jackets, but haven't seen a reversible jacket with sewn logos from that era. So I took a chance on it. At a final price of just $100, which I think is mostly the condition and that likely nobody looked at it up close. Even if it's not Lombardis, I'm fairly confident it's a real Braves warmup from 1942 ish.

On the other hand, sometimes it's the circumstances of the sale, even when nothing else makes sense.
This ball was in a box of old baseballs at a flea market. If nothing else, it's a nice old minor league ball, and I'm in at the asked 50 cents. Especially with the way it's written on.
The guy told me that "that's like little league or something. I have some other autographed balls if you're interested" All the others were "signed" with a very worn magic marker.... I thought they were all very suspect.
But looking it ... It hits none of my usual ideas about what makes sense.
The player did play in that league.... a year
after he signed this.
I found it in an area that he seemed to have little connection to.
He played for Cincinnati in 55, and the Giants in 56. he was sold to Seattle in the PCL in October 55, and drafted by the Giants in November 56. He was from NY, so not such a stretch, especially considering he was originally from Yonkers. Pretty tight timeline perhaps, but not as crazy as it seemed.
So the guy with some very sketchy "autographed" balls somehow ended up with a real one that's not super valuable, but pretty cool, and tossed it in the "old baseball" box....

