There has been quite a bit of talk about Lululemon after the transparent pants issue. I have also seen some articles about how poorly people have been treated in their stores if they aren't a thin person.
I am going to put it out there: I am overweight, and I love to practice yoga. So those articles hurt my heart. I have been there. I have been treated poorly simply because I don't fit into a size 6 or less.
So what do I wear for yoga? I cannot justify spending $60-$150 on one item. So I tend to just look for cheaper sports gear. For pants, I buy the "yoga pants" from Kohl's (example). For less than $20, you can get a decent pair of pants or capris that will last you a long time.
For shirts, because I sweat quite a bit and don't like being warm, I just wear a cami. I get these from various places, including DEB (example) and Wet Seal. They allow freedom of movement and don't keep me too hot.
Another issue with being slightly larger, is I have a large chest. I wear a 34 F bra. Yup, an F cup. So by the time I get a sports bra big enough for the girls, it isn't tight enough under them to support them. They start slipping out, and that's not good.
I tried finding sports bras that work more like a regular bra, with a clasp somewhere. One I found zipped up in the front. I thought it was cute, and since it would clasp around me, it would be tight enough. Unfortunately, as soon as I zipped it up and let go, it unzipped. I tried zipping it up again, and it once again unzipped. Needless to say, my husband loved that sports bra, but I didn't.
Now, I just wear my regular bra. It's not easy finding any bras in my size, let alone sports bras.
So all in all, I probably spend about $30-$50 on a yoga outfit. There are a lot of cute things that I see in emails and catalogs for yoga gear, but I really can't justify spending so much money.