Learning Request Approvals are not triggering

Summary

Set up an approval on the basis of the course having the minimum price field populated

Content

Hi, 

i've set up an approval with the following condition: 

((Learning Item.result.Learning Item Type != "ORA_NON_CATALOG") AND ((Learning Item.result.Minimum Price > 0) AND (Learning Item.result.Minimum Price != null)))

Meaning if any catalogue requests have a price against them, it should go for approval.

However, the approval process is not triggering. 

Is there something in the setup of the course that needs to be altered to allow this to trigger?

Thanks, 

Nirupa