Hyvä migration alongside the upgrade, what’s the extra cost?

Hyvä migration during the upgrade is cheaper than doing it later, because you’re already in the codebase, but it doubles the project surface area.

Realistic cost split for a typical $5M GMV store on Luma 2.4.6:

• Upgrade only (Luma → 2.4.9): $8k, $15k.
• Upgrade + Hyvä migration combined: $30k, $55k.
• Upgrade now, Hyvä later (in 6 months): $8k, $15k + $25k, $45k. Total $33k, $60k.

So combined is ~10-15% cheaper than sequential, but adds 4-6 calendar weeks to the upgrade and roughly doubles the testing burden (Hyvä changes every storefront-facing template and every extension’s frontend hooks need re-validation).

Decision rule: combined wins if you’re already planning Hyvä in the next 12 months, and you have the budget + calendar runway. Sequential wins if upgrade is urgent (security patches, support deadline) or if Hyvä isn’t locked-in yet.

I’ve shipped both patterns. The combined-upgrade is the more popular choice for stores at $2M, $10M GMV; sequential is more common at $50M+ where the calendar-time impact of doubling project length is the constraint.