Sometimes you will need to adjust accordingly. Sometimes you might have to lower your price and make slightly less profit. In other cases where you lower your price on some candles you can make up for it with other candles. You will really just have to see what works for you. I work for a major freight company and I can tell you that your packages are not handled the way you would handle them yourself.
Boxes are subject to being thrown, tossed, dropped and crushed.
There are things that you can do to combat the freight handlers though. Never exceed the weight amount for your box. Also keep in mind, the heavier the box the more likely it is to be dropped. Use plenty of popcorn and bubble wrap. Try to avoid going directly over the same tape but overlap as much as possible.