Some people do not understand the rewards of doing things yourself. I have always done most stuff myself, and with my hubby of course for the heavy stuff and we have laborers that could do it, but it's a kind of peaceful therapy to do it yourself. Tell here you are a perfectionists and would never trust a lawn company to do it.
Btw, $400 for having a landscape company lay mulch is sounds pretty cheap if they did her whole landscape....just sayin. The average charge to lay mulch is about 75 to 100 bucks a yard just for the labor. Ridiculous I know, but many people can't do physical labor.