If your at the backend login screen choose "Dansk" as language, there is a discrepancy between Ecommerce and PIM when it comes to the use of decimal separator.
If you in PIM try to use comma as decimal separator, it is not accepted.
This applies to both price and any custom product field of type "decimal".
In Ecommerce it works as expected:
It would be nice with a consistency, so we know what goes, and what doesn't.