Question: What do the various options in 
Valuation Based On Field in Bill Of Materials (BOM) Form mean? 
Answer: There are 3 available options in the 
Valuation Based On field;

- Valuation Rate: 
 
- Item valuation rate is 
defined based on it's purchase/manufacture value + other charges. 
 
- For 
Purchase Item, it is defined based on charges entered in the Purchase 
Receipt. If you don't have any Purchase Receipt
 made for an item or a Stock Reconciliation, then you won't have 
Valuation Rate for that item.
- Price List Rate: 
 
- Just like you pull item prices in sales and purchase transaction, it can be pulled in BOM via Price List Rate.