They occasionally have free shipping deals, but usually when that happens, the otherwise free stuff is 80 per cent off instead of free
Depending on where you are from, the cheap shipping actually arrives at the same (I learned that the hard way when I ordered business cards for my photography business and paid for the fast shipping and my high school co-op student ordered the cheapest shipping and got his at the same time). If you are in Ontario, go for the cheap shipping, they are located in Windsor.
Once you buy from them once you will get daily e-mails from them about their various deals.
Another tip is to go on different times of day. I had prepared my business cards at work and they were free, when I went home to actually order them, the price had gone up. They are usually cheapest from 9-5.