I have been researching this topic myself since I had to cut my lovely long hair for a job.
Anything decent is going to be a few hundred dollars or more.
That said, there are Chinese websites that have wigs for ridiculously low prices. I almost bought one last night just to check it out. It was a lovely looking long hair wig with a wave for $15. Seems unreal. Just don't trust the Chinese internet. Could be the hair from starving North Koreans or something ... don't know.

But, if you want a good wig my research has shown that you need to spend some real money. Google is your friend, all the sites will pop up.