SEO & SEM backlinks monitoring tool

I was looking for tools like xovi to optimize and track my website. Can you please suggest me an affordable and reliable seo & sem backlinks monitoring tool.

I already know about seomoz so please avoid it. I am looking for something which is more cheaper than it.

Thanks in Advance.

Sorry, but this forum is only for questions related to DMOZ.
We are not about SEO, SEM or wathever other SE tool.
You might find a usefull forum to ask your question by looking at our directory, http://www.dmoz.org/Computers/Internet/Web_Design_and_Development/Promotion/Chats_and_Forums/