$40 is cheap for a 35 DA placement, and the usual reason is nofollow policy, small traffic, or both.
Educational publications keep their pages for years, which is the main reason to place here: a genuinely useful admissions or study guide is consulted on the same dates every academic year, so a link inside it keeps being crawled long after a news article would have decayed. It also means the bar is set by the site's own reference-style content, and a thin promotional contribution stands out badly.
Within the Education section of the index — 30 listings, 54 median DA, 3.1k median traffic, $40 median price — this placement is within a few percent of the median on cost and roughly 70% of the index median on audience. Listings in that section range from $20 at the cheap end, so the question is not whether $40 is high for a link, but whether it is high for this one.
Also expect strict link limits, usually one, and frequent nofollow rules on institutional sites. A 35 DA educational page with 3.9k monthly visits is worth having in your profile for plausibility and citation, and you should not expect it to shift a competitive keyword on its own.
The index lists this property's editorial links as followed. Availability of a followed link changes with the site's monetisation decisions, so we confirm the tag on the live URL before counting delivery.