In order to get one cubic yard of mulch, you must purchase 13.5 (2 cubic foot) bags. There are a total of 27 cubic feet in 1 cubic yard. To reach 1 yard of mulch would requires a purchase of 13.5 (2 cubic foot) bags. A cubic yard is 27 cubic feet. So by multiplying the bag price by 13.5 we will get the cubic yard price.
A 2 cu ft bag of brown mulch costs around $3.60. You need 13.5 bags for a cubic yard. At $.3.60 that's $48.60. A cubic yard of bulk mulch can be found for $23 to $38 at some places. That is more then a $25 per yard difference.
However, the price difference is eliminated if you buy torn bags that are 50% off at Lowe's.