Well, even cheap mulch would have been $75 bucks delivered, versus the $25 I spent on landscape staples (to secure the replacement landscape fabric I found in the garage), so I guess I saved $50. I live in the city.
I'm usually pretty laid-back, but neighbor kids play there, too, so I erred on the side of caution.
Except it's still stupidly dangerous because the previous owners installed too larger a play structure in too small a space. Falling off and hitting one's head on either the privacy fence or the concrete sidewalk is quite possible. Sigh.