Prices Labels are set in Item Prefs. Depending on settings you may see up to 6 Tabs. Names for Prices appear on Preferences, Advanced, and Advanced + for 5, 15, and 30.
Prices Labels let you set names for Price Levels to help wherever you use Price Levels. Price Level 1 is usually Retail or full price. It is the price used when others are blank.
You choose 5 Prices, or 15 Prices, or 30 Prices and then choose how to use, for a group like Wholesale or for one customer with whom you have agreed pricing on many items.