SEO expenses break into recurring costs and one-time investments. Monthly retainers typically run $500–$2,500 for local businesses, $2,500–$7,500 for competitive regional campaigns, and $7,500–$20,000+ for national or enterprise efforts. That covers strategy, technical optimization, content planning, and reporting. One-time costs include technical audits ($1,500–$5,000 depending on site complexity), site migrations ($2,000–$15,000 for large catalogs), and initial keyword research packages ($800–$2,500). These front-load the work so monthly retainers can focus on execution. Content creation is often the largest variable expense. Professional SEO articles cost $150–$800 each depending on depth, research requirements, and writer expertise. A site publishing two articles weekly spends $1,200–$6,400 monthly on content alone. Product page optimization, category rewrites, and technical content for SaaS companies sit at the higher end. Link building budgets range wildly. Scrappy outreach campaigns run $300–$1,000/month. Competitive niches requiring digital PR, journalist outreach, or sponsored placements need $2,000–$5,000 monthly. Enterprise brands chasing authoritative links in finance or health allocate $5,000–$15,000+. Tool subscriptions add up: Ahrefs or SEMrush ($150–$500/month), rank trackers ($50–$200), schema markup tools, page speed monitors. Agencies absorb these into retainers, but in-house teams budget separately. At Ottawa SEO, we separate technical foundation work (audits, site structure, Core Web Vitals fixes) from ongoing content and links. A typical Ottawa client launching SEO invests $3,000–$5,000 upfront, then $1,500–$4,000 monthly depending on market competition and content velocity. The biggest mistake is underbudgeting content while overpaying for reporting dashboards—rankings move when you publish and earn links, not when you check them.