Full Answer
GTM server-side implementation requires cloud hosting—Google Cloud App Engine starts at $120/mo for a production environment—plus container configuration, tag migration, and quarterly maintenance as platforms update their APIs. At $120/hour and 50-120 hours for initial setup, entry costs alone reach $6,000-$14,400 before any ongoing work.
Over five years with regular platform API changes, total cost reaches $70K-$145K for mid-market stores. Enterprise CDPs like Segment or mParticle charge $50K-$500K annually on top.
WordPress-native server-side tracking eliminates the developer dependency. Transmute Engine covers GA4, Facebook CAPI, and Google Ads for $8,940 over five years, with each additional platform at $10/month. Setup takes 11 minutes. No cloud infrastructure to manage.