Hi,
As per SAP standard Text item - AGTX is for informational purpose and hence pricing would not be applicable.
FOr a text item Pricing cannot be made Pricing relevant (based on SAP Standard coding) - It is driven by Item Type.
Hence, copy AGTX and create a Z Item category also make sure you select Item Type as "D".
Now Pricing field would be active - option as "X".
Please let me know for any further clarification.
Regards