Legacy Modernization Cost: $50K to $5M+ in 2026

Metric Value Monthly cost per MIPS for mainframe systems $1,500-$3,000 Average budget overrun on modernization projects 27% Higher revenue growth from rebuilding vs patching 4.2x legacy modernization cost is the core decision for any data-heavy application: you either prioritize real-time concurrency (Node.js) or deep data processing (Django). Legacy modernization budgets blow up. 68% of projects exceed their initial estimates by 27% or more. Yet companies that push through see 4.2x revenue growth within two years. Gartner reports that 91% of IT leaders increased tech investments in 2024, with legacy modernization topping their priority lists. The math is brutal but simple: keep patching that 20-year-old system and watch competitors eat your lunch, or bite the bullet and rebuild. Cost ranges follow predictable patterns based on company size. Small businesses typically spend $50K-$250K modernizing core systems. Mid-market companies budget $250K-$2M. Enterprises? They're looking at $2M-$