[Some guidance would be most appreciated. An SEO company that I have used before has contacted me offering a monthly list of the following: 100 x pr 5 & 6 blogs for commenting on Mix of following and no follow, Not scrape box harvested, Mix of foreign and USA blogs. They want 35 dollars a month for the just the list, I would have to do the comments myself. I am keen to diversify my backlinks and wondered if this was a good price? What would you pay for this monthly list?]
That seems like a reasonable price, however, I would be concerned about that exact same list being distributed to a large group of spammers. In other words, if they are compiling that list for your use exclusively, it is a good value. But, if that list isn’t for your use exclusively then it is of far less value.
I wouldn’t invest too much of my effort in such a list. It only takes a handful of other list holders to taint the entire list. This could result in the bulk of your efforts being deleted, or even worse you could end up being branded a spammer and put onto a blacklist that wipes out all your valuable contributions to websites that filter against that blacklist.
I’m not saying don’t use it, just limit your exposure by doing other, less volatile, promotional activity. Personally, I would not use a list that was distributed to a hundred other internet marketers.