I've seen a few products that claim (and really seem to work) to let you track estimated budget and keyword data from competitor websites. This could be a good aid in jumping into a new stream.

Any thoughts on the usefulness of these products?

Has anyone seen either of these products or is there something way better that I am missing?

http://www.spyfu.com/
http://www.keywordspy.com/

I use spyfu, but I don't pay for it, so I am satisfied. It is good enough to see what competitors are doing but without a lot of data.

I have the same question too, and also need to know if www.semrush.com is a valid tool.

Thanks.