I am currently helping a friend finish the design of her 2-bedroom condo. When it came down to the selection of window treatments, I knew the space (especially the living room) needed a wow factor. The living room has an almost 10 foot wide window and covering it with standard premade curtain panels would blow the budget.
My friend is lucky — she knows someone who sews on the side and has offered to make drapery for her. We are going to pick up a bright, colorful print fabric and try to keep the price under $30/yard, which fits right into the budget! If you have any friends who sew, don't be afraid to purchase fabric and have curtains made. If you are on a really tight budget, my go-to fabric store is Michael Levine.

Purl Soho: The Globalweave Embroidered Fabrics from India (featured above - left) is $23.40/yard
Ikea: The Kajsastina Fabric gray/white (featured above - right) is $6.99/yard

Britex Fabrics: The Italian Plum Floral Cotton Fabric (featured above) is $22.99/yard

Mood Designer Fabrics: The Cherry Floral Print is $25/yard
Other Fabric Store Sources:
Images: Purl Soho, Ikea, Britex Fabrics, Mood Designer Fabrics

Commercial Flour Sa...
I love the Kajsastina fabric - I'm using it to create large fabric flags at my wedding reception.
I made curtains from that Ikea fabric! Well, the yellow fabric, not the grey, but the same fabric! I made matching throw pillows from the grey.
The fabric is so perfect because the sun shines through the white flowers.
http://www.improvingthepicklejar.com/2011/04/french-door-window-treatments.html
Love the Kajsastina Fabric in gray/white ! I used it to make curtains for our guest room.
Fabricguru.com
If you like vintage style fabrics (I'm talking Victorian and Edwardian), Joann's has tons of fabrics... I frequently use the home decor fabrics for costuming, since the brocades are perfect for antebellum costumes. But I have seen a few that I would use in my house.
I am surprised to be a fan of CalicoCorners.com. They have a great collection of fabrics including Dwell's complete collection and a great line from Thom Filicia. They've completely broken out of the fussy traditional market and offer very affordable, fashion forward textiles.
I used the IKEA Kajsastina Fabric to create a hanging panel in our dining room. I originally wanted a large piece of art, but we just couldn't afford it. 2.5 yards of this fabric and one of IKEA's hanging kits- Voila! It makes an impact, but isn't too arresting on the eye. It is an excellent choice!
Marikimo also has great textiles, though the can get pricey.
lsfabrics.com and buyfabrics.com
Tonic Living has a ton of gorgeous home decorator-weight fabric for around $20/yard.
re: "If you have any friends who sew, don't be afraid to purchase fabric and have curtains made."
If you have friends who sew clothing, they might tell you to sew your own damn curtains. LOL. This is a popular topic on sewing discussion forums and blogs. Maybe quilters are a friendlier bunch.
I love IKEA for their prices and cute fabrics.
Absolutely LOVE IKEA fabrics. I find them to be the affordable version of marimekko style fabrics. Bold, beautiful, and good quality.
And, making curtains or pillows is a great way for the sewing friend to teach the non-sewing friends how to sew. Lots of straight lines...easy!
Your friend is quite lucky. My place has four giant windows and although I love the natural light summers in Texas are hot. So to save money I've been researching window treatments and they are costly for four large, almost floor to ceiling windows.
@aLittleSewing: seriously, talk about Touchy Subjects. This is a big one among knitters, too. Just because your friends are crafty doesn't mean that they don't value their time, and I have never understood the thought process that would lead someone to misunderstand this. Yo' friends ain't yo' own personal sweatshop workers, people! If you want curtains from fabric, get industrious and...you guessed it...learn to sew, 'cause it's really the only reliably polite way to do this.
AMEN aLittleSewing and shanalulu!!!! My unit secretary actually asked if he couldnt bring his elderly mother's mending in for me to do. Barely know this person. And I also love Ikea fabric, in addition to great prices and design it sews up like a dream.
I'm crafty (mainly knitting, but sewing, too), so I totally get that you should never EVER ask someone to knit you a sweater or make curtains for you. But I would have no problem with a friend asking me to teach her how, or to help her do it herself. There's a big difference between asking for help and asking someone to work for free.
@themegnapkin: absolutely. And you get pretty good at differentiating those who really want to learn the skill in question from those who are excited now, but won't stick to it, and will probably end up hoping that you'll take over and finish it for them...it's just no fun to have The Talk with the second. Which is why crafty types, by and large, prefer not to be used as a Resource Via Which to Get Cheap Stuff -- because many people are thoughtless and inconsiderate. Ask a good friend, sure, if you're committed, but...meh. I don't like this "just gitchoo some fabric and shanghai a friend who sews!" advice being tossed around willy-nilly, as it typically ends badly and with the favor-doing friend being painted as a jerk for not wanting to slave for ungrateful/flighty people for free.
maybe ask to borrow their sewing machine, but seriously, curtains are not advanced sewing technique.
We have a simple curtains tutorial on our blog, as well as how to join fabric panels to match images. http://theneedleshop.net/blog/?p=64