Scented candles are nice, unless they are overpowering. When there are scented candles or wax burners scattered throughout the house, potential buyers tend to feel bombarded by scent; especially if there are several different scents burning. The common consensus to this scenario is "What are they hiding?"
If you want your home to smell inviting and "homey", less is more, have just one scented candle or wax burner in the kitchen, trust me, it disperses throughout the house. Avoid floral scents or the newest combination scent on the market, these are generally very strong and I've had potential buyers with allergies be too distracted to actually look at the home because they need fresh air and just want to leave. Keep it simple, a plain vanilla or cinnamon scent smells like baking, a citrus scent smells crisp and fresh.