Calixto's Shop is permanently locked. (cannot sell amulet)

[kyzzlebops]

May have been my fault, I forgot about the selling step to convert the amulet to Necro and went to the flier-maker instead. Now his shop is always locked, always on trespass mode, and I cannot talk to him at the inn.

[The SheoDovah]

Calixto isn't a merchant and unfortunately, because you've gone to Victoria(or something V) you've started the final stages. The only way to do it is to reload or if you are on PC, use the console commands to spawn the full one on him.