Clearscope charges $199/month. SurferSEO charges $89. Both do the same fundamental thing: fetch top SERP results, compute TF-IDF, show what terms you are missing. This does it in the browser for free, using DuckDuckGo for the SERP.
Read the story behind this tool: Mega SEO Analyzer v2 — Clearscope-adjacent in browser.
Related: AEO tool stack · Why v2 beats a subscription