Each given product can have various prices: regular, volume1, fallpromo, etc. Those are the price "name" or as the field is called, "PriceCode". When the user create a price, he gives it a name or can use one from the dropdown. (Drop down value list is from field).
Each price code is "semi unique" in a sense that it must be unique for each product's prices found set (subset of all prices) but can be repeated across various products price sets.
How do I prevent a user to create two price lines with the same PriceCode for a given product?
1-Validation (how do I prevent the user from bypassing the warning, since I cannot check the "unique value" box?)
2-Script trigger (How do I restrain the validation to check the ProductCodes to only the prices of the current product?)
3-Preventing a string to appear in the dropdown if one of the price lines for that given product uses that code.