I want to a lookup to PriceBookEntry on a custom object. SalesForce does not give me an option to create a lookup to PriceBookEntry, it only gives an option for PriceBook.
Kindly tell me how should I proceed with this requirement.
Unfortunately this is not possible.Idea has already been raised earlier.Please check the below link
https://success.salesforce.com/ideaView?id=08730000000ZimNAAS
I have never tried this on before but this could be possible via Trigger because PriceBook Entry is available via API.You don't need need to create Lookup field.Just create Text Field that stores value of Price Book Entry and you need to write a trigger when you create a record or depends on the your requirement(Edited too).
You can give it a try.This could help.