Hi Swayam,
Instead of using the perform userexit_new_pricing_vbkd, try to use the perform userexit_new_pricing_vbap. You can set the new_pricing indicator as per your requirement based on the comparison of the structures XVBPA and YVBPA. If these structures are not available there, then you can use field-symbols.
Regards,
Shashi Thakur