Wow, that's a tough one. Shade, 3 ft high, spreading grass for warm zone 9.

Not much comes to mind.

Chasmanthium latifolium would fit in well with Bamboo. You'd have to keep it moist in zone 9 and definitely in some shade. It's clump forming actually, but can be planted to form a hedge-like grouping...without distinct individual forms. Does spread with rhizomes, but not overly aggressive and easy to control. In shade it will be about 3 ft with a slight droop.

I google imaged that grass and i like how it looks. Now, where does one go to purchase said plant?

Nevermind. Behold the power of google. I found it for around 11 bucks. Sound reasonable?

Bluestem, Santa Rosa Gardens, Digging Dog, Plant Delights, High Country Gardens, and lots of others sell online grasses and should carry Chasmanthium. I've seen it for less than you mentioned, but depends on what size you're looking at.

I second the recommendation for Chasmanthium latifolium or River Oats. Although it doesn't spread by runners, it readily reseeds and will quickly fill an area. It also grows great in the shade and is about the right height. It is a beautiful grass suggestive of bamboo with very attractive seed heads in late summer.