Copying my comment to an answer as it seems it helped.
You are trying to set the result of comparison between your field and number to the result field, the result is Boolean and it does not suit your formula. Just leave it as 1000, that should work.
Based off testing by myself and Thomas Taylor, neither Custom Settings or Custom Metadata values are accessible in Row Level Formulas at this time.
A workaround to referencing this data in a Row Level Formula is to create a Formula Field on the Object referenced in the Report that pulls the Custom Setting field or Custom Metadata field required.