Is Photography the Best Deal in the Art Market?

From this vantage point, nope.

But I don’t think comparing both (a bubble and a niche market, except for a few odds like this expensive piece of sheet) makes much sense right now.

But to be fair, price irrationality isn’t the only factor for this asymmetry : a 19th-20th century painting is obviously more valuable then any photography will ever be.
So my guess is that to compare both mediums fairly, you need to be equally unfair, like this Bloomberg report, and reverse periods : the old masters of photography from the first half of the 20th (HCB, Klein, Brassaï) against 21th century contemporary painters.

Maybe that would help, maybe not —Chinese painting is quite expansive while worth it.

→ Bloomberg