Cheap Yoga Classes :

Special promotion for yoga class at YogaWorks. 2 weeks of yoga for $25. Here's the link :http://www.yogaworks.com/newyork/promo.asp
I think that YogaWorks does vinyasa style yoga.

Some Like It HOT Yoga 206 East 63rd Street tel: 646 840-0108
Introductory Special : 1 unlimited yoga class for 7 days for $35.00
www.somelikeithotyoga.com
This studio only teaches "hot yoga", Bikram or Power Vinyasa. These are strenous yoga practices. Also, the hot yoga and Bikram are done in a room heated to about 100 degrees to make you sweat. This is not a recommended yoga style for you if you suffer from high blood pressure.

So take this opportunity to try out different styles of yoga. Even if you dont like it, it is an education and you will pick up some extra tips along the way. I am a firm believer in trying out everything, that way you learn what really works for you.