It depends on couple of things. I've worked with couple of them before on gambling links and that can become a bit expensive, but still, the websites are a bit spammy. Filmdaily.co for example has lots of RDs and it does look Okayish, but at the same time it's really spammy. If you are going for non gambling/cbd/adult related stuff, i am pretty sure you can get a price around 50-100$ for a guest post, less than 50$ for link insert in old articles. You should really check their domains before doing anything. If they lost some major traffic, it's better to don't go there at all. Lastly haggle as hell to get the best price.