What do you mean insane? That's a fair amount of beds. I'm use to metric but I'm thinking you'll need around 45 cubic yards at around 3" thick ..depending on how dense the shrubs are. Charge accordingly....would be around $3300 for me.Thats with little to none prep work...Nice small job.
I'm with Kris and NCSU-45yds of mulch,installed with no edging for $3150.00 + tax. Edging would be around $ .90ft depending on existing bed definition.Don't forget to upsell pre-em treatments in spring and post-em treatments during the summer. Good luck..
Without seeing the site, and assuming "best" case scenario, with no pre-emergent application or tax (now we have to charge not only for materials but labor too- 6% each!), I was coming up with a quick figure of $2500. That was roughly 47 yards, spread at 3" thick.
That number is assuming there is not a lot of perennials to be mulched around, no hills and easy access. Any of that changes, and the $$ goes UP.
If the customer has that much bed area, they shouldn't be surprised at the cost...
Don't shoot yourself in the foot just to get the job! (as many times as I've said that recently, I ought to make it my sig line!)