It's not unusual for non-competing companies to cross promote each other by offering discounts or specials to each other's customers. If you belong to an association or shop frequently at specific stores, you may be eligible for discount candles if they've paired up with a candle company.
If you have a membership card in an association some candle companies may allow you to show your membership card and receive discount candles when you shop there. Be sure to check with any clubs or associations you belong to and see if membership with them offers you a discount with other stores.
Companies are always looking to reach their target market in new ways. Look for cross promotions between similar types of businesses such as bath and body stores or home décor stores that may give coupons for discount candles at a store they have chosen to help promote.