Where do investors buy curtains and window treatments?

[Jack Gray]

For high-end rental properties, where do people find window treatments (blinds and curtains) at a reasonable price?  

I ask because we're working on updating a 4 bedroom single-family that will rent for $2,800/month and my wife just spent $800 on floor length curtains for two windows from Pottery Barn.  There's got to be a better way.  

On the last house I renovated (also a high end single family) we bought blinds at Lowe's and curtains at Pottery Barn and it was over $2,000 just for materials.