From Beyond the Grave is a anthology horror film from Amicus Productions in England, a studio that released seven such films between 1965 and 1974. (It's also the third film in this countdown to feature Donald Pleasence!)
The stories all start out with a visit to an antique store run by a spooky dude played by Peter Cushing. If a customer cheats the owner in any way, say by lying about an item's authenticity, or swapping price tags, then you can be sure those customers will pay another price in some way.
There are three main stories in the movie. The first features David Warner, who turns into a serial killer (perhaps practicing for his role as Jack the Ripper in Time After Time a few years later?) after buying a mirror.
The second story involves a stolen medal, Donald Pleasence as a war veteran selling pencils and matches on the street, and a businessman in a loveless marriage. (Donald Plesence's real daughter, Angela Pleasence, plays his daughter in this story.)
The final story involves an ornate door that opens up into an occultist's world, trapping souls inside. (It's probably my least fave of the three.)
I watched From Beyond the Grave on TCM, and it is also available as a rental from Prime Video.