Hi Prashant,
A first you should create a status profile in BS02 and assign this to your Sales order type VOV8
it should contain BLCK, INIT as statuses
and BLCK to be activated to Forbid the creation of Delivery
In Pricing procedure, you should set up a routine to check the Document Net price should not be less than Bottom Price, if so it should trigger the BLCK status using the user exit " USEREXIT_SET_STATUS_VBUK" in the include LV45AP079
Please check with your ABAPer and provide the logic , As part of configuration you have to create a new status profile under BS02 and assign this to the document types, rest should be achieved by program modifications
thanks
santosh