Best SD user exit to use for checking 'material pricing conditions' (KOMV-KSCHL)

Hiya,

When creating a sales document I'd like to check the material pricing conditions (KOMV-KSCHL), specifically for rate(KBETR), when a material is entered into an order.

If the Rate value is not as expected then I'd like to raise a pop-up to inform the user.

I was searching for a userexit to use and I can't find anything that fits my requirement...

I was therefore thinking of using USEREXIT_PRICING_PREPARE_TKOMP or USEREXIT_PRICING_PREPARE_TKOMK.

But I thought I'd just check with you experts first.

Would anyone have any suggestions?

Thanks in advance!