Nowhere near as pricey as the planter! Those are nice planters! If you make your own 511 mix, you could probably do it for about $30. Not sure how much 14 cu ft of premium potting mix would cost. Either way whether you got the planter as a gift or purchased it yourself, the cost of the mix is a worthwhile investment IMO, and only about 10% of the cost of the box.

I just got my first Gardeners catalog (I'm a new gardener) and saw those. They use those same ones (the bigger 380 quart) all over Epcot for their flower and garden shows. I'm a container gardener and was thinking that would be perfect to add to the backyard. I've seen around the net positive results and opinions about their soil and honestly the price isn't that bad for Mix.