What is the right price for a promotional article/video?

A while ago i asked a blogger to post an article on his blog. The post was provided by me , so i would have saved him a working hour as well..
He asked me $100 or $150 for that (don't remember), with only nofollow links allowed in the article.
I was shocked by the price (and by the nofollow), because that site had a low Alexa ranking and no user comments on neither of the articles.
So i had a feeling that the blog has low traffic and the money he pretended was too much, and i refused.

I have difficulties calculating the real value of promotional services all the time, so i am asking you what are the parameters & measurement tools we should use to "evaluate" a blog/vlog , and be able to judge if marketing there is overpriced or not.

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First part of the question: how to estimate the number of views/reads your promotional article/video will have in 5* years.
What are the usual methods & tools for the estimate ?

The only things that come up to my mind:

- do a domain lookup on Similarweb , Ahrefs and Alexa. Are they useful in some way for estimating his pageviews & uniques?

-If he's a Youtuber, check the number of subscribers and the views for his videos about a similar topic as yours, and estimate that your video will have roughly the same views

- look at the blog/vlog: observe if it is professionally made and the blogger is professional enough

- user comments: if it has no comments, should i assume it has low traffic?

- social community: ask him what is his Twitter and FB page, to check how many social users he can reach after sharing the post/video on his FB/Twitter/etc. ( i know, many followers can be fake/bought, but i hope there's a way to tell )

Other tools and methods of analysis?

* i assume that, with rare exceptions, any content will not have significant views after 5 years from being published. Correct me if i'm wrong

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Second part of the question: what is the maximum acceptable price, based on the estimated reads/views?
Or more in general, what is the right CPM for a promotional article or video?

I know it must be somewhat higher than a banner CPM, in that a banner has a lower engagement potential than an article, because when a user is reading the article, you know he is really interested in the topic and his attention is there, while the banner may be unnoticed.

But i think many bloggers exaggerate a bit with their quotations.

Thanks

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p.s. Of course, what counts more is the cost-per-lead you are going to pay, not just the CPM.
A Lead can be defined as a visitor that reaches to you from the promotional content, or even as a buying customer.
But for figuring out the cost per lead you got, you have no other way than buying the article and measure the performance afterwards, as IMO almost no blogger give you the possibility to pay just per lead.
So you have no other choice than to spend money to have just impressions (of promotional content), and then make performance measurements against your Leads.
But if you can at least estimate the first thing, you can estimate the Leads as well :you already know that , say , 10% of the people will actually take a look at the promoted site/product, and 10% of them will be actual buyers.

 

I believe $100-$150 are being charged by some professional bloggers who have decent number of subscribers. You should ask him the number subscribers he have , twitter followers, facebook followers. If he also have a Youtube channel with good subscriber . What is the bouncing rate to his blog articles or vlog videos. How many page views he is getting on his content. If you feel his subscribers may be interested in your services then it could be worth else not.

 

@AlphaNine_Vini
Asking him about his traffic/followers/engagement is a not good idea, unless you verify the stats he claims to have.
What prevents him from lying ?
About social, you can ask him what are his profiles on TW, FB, YT, then you better go there by yourself to check how many followers he has there.