I'm putting up a small storage bldg. 12x24. Right now it's just a frame. Ideally, I'd like someone to tell me where I can get premade, prefinished stucco wall panels in Northern California? I saw them available back east. But if that's not an option for me in Nor Cal, and keeping cost low is the primary factor... Should I put up cement board and stucco to it? Avoiding the mesh step if I use plywood exterior instead? Or plywood and stucco?

Also, I feel confident to put up plywood or cement board, but would have to hire someone to stucco (hence the pre-finished stucco panels would be ideal for me)
thanks,
LS

I'm in the NE, and here many sheds are sided with T-111 tongue and groove plywood siding. That's the cheapest. There are 2 qualities/prices.
My shed is what I call batten board - rough pine 12" wide with 2" wide furring as battens.
Anything stucco is bound to cost more than most common materials.

For longevity, Hardie Board is very popular for many applications, including siding. It must be painted. It's a mix of concrete and sawdust and epoxy.
http://www.jameshardie.com/d2w/best-practices/hardiepanel-hz5-ca-en.pdf
It is NOT the cheapest in the short term, but it is the best in the long term.
No one around where I am stocks it, but they stock backerboard and clapboard.
I'm sure you can order it through any lumberyard that sells Hardie.

I'd use Hardie "Board and Batten", 4 X 8' sheets. Many Home Depots stock them.