Selling commences in 30 minutes (going to Stage 2 - Diablo Approaches)
Selling concludes in one hour (Stage 6 - Diablo Invades)
Double/triple check that your game is in Hell and on North America. You can change region with the world icon above the Play button on the launcher on PC.
If you are not in Hell yet (Act I is fine), you have an hour to get there.
It is possible to be on Hell in NA and not get the Stage messages but D-Clone still spawns.
If you need help, DO NOT LEAVE TOWN. Let your helper find and kill D-Clone. Searching for D-Clone sucks.
Best to uncheck the box allowing friends to join, make your game private (with a password).
Good luck to all, hoping for lots of 20s!!