Customer Groups
Reduced pricing for certain customers can be done using Customer Groups. To create a customer group go to Admin -> Billing -> Customer Groups and enter a name, such as Senior Discount.
Next you will need to assign the customers you want to have this discount in Income-> Customers. Select a customer to edit. Scroll down until you get to the Customer Group field then enter the group name (under General -> Additional).
You can set pricing for the customer groups by going to Inventory -> Items. Select an item to edit. At the top of the page click the Customer Group button. Check the box in the Include This Item in This Group column if you want special pricing for this item. Set the Special Price. When a customer in the selected groups purchases the product, the special price will be used.
If you would like to give blanket discounts by a certain percentage off the current price of items, you can use Markdown Price Levels. This will let you create a specific price level that is, for example, 10% off of the current Retail price level. Go to Admin -> Inventory -> Price Levels -> Add. For the option Markdown Based On, select the existing price level you want the new level to be based on. Enter in the Markdown Percent (10 for the example). You can enter a negative number, and the system will increase the price by that percentage.
You can also give discounts on specific items to individual customers. See Admin -> Inventory -> Customer Item Discounts.
If you'd like additional control over special pricing, check out the Special Sales Pricing add-on by going to Admin -> Inventory -> Special Sales Pricing. Here you can set date ranges for when special pricing is available, which customers, jobs, and branches the prices apply to, and you can base the price on a target margin using a static cost.