For the full suite at lower cost
SEO Smart Engine covers Site Explorer-equivalent audits, rank tracking, keyword research, content tools, and backlink analysis at ~50% of Ahrefs pricing - plus AI visibility, which Ahrefs does not offer.
For pure backlink data
Majestic (cheaper, different index), Moz Link Explorer (smaller index, easier UI), or LinkMiner (project-based pricing).
For keyword research
KWFinder or Ubersuggest - cheaper, less deep, easier to learn.
For technical audits
Screaming Frog (free up to 500 URLs, one-time license after that) is what most agencies actually use for crawls even when they own Ahrefs.
What you give up
Ahrefs' Content Explorer and their sheer index size. If your job depends on finding every mention of a topic across the web, Ahrefs stays worth it.