Price Lists are useful for orders and invoices. An up-to-date price list helps in decision-making even at the lower levels of the organisation and quickens the sales process. Tally assists in creating quantity based pricing with complex discount structure. Price Lists are available only for inventory items and hence the feature is available only if inventory and invoicing are activated for the company.
You can have one or more price lists. You require more than one price list, when you have different price structures/levels for different purposes, usually, different groups of customers requiring different discounts or dealing in different products.