Answer
The second LPAR or physical system alone is often the largest line item once a buyer looks past the software quote, since it typically needs enough capacity to run production workloads if a real failover happens, not just enough to receive replicated data passively. Bandwidth costs follow close behind for environments with high transaction volumes or large IFS objects replicating continuously between sites, particularly when the two systems are geographically separated for genuine disaster protection rather than sitting in the same building. Buyers building a budget should ask vendors to itemize these costs separately from the license fee rather than accepting a single bundled number that makes comparison across vendors difficult.
The ongoing costs matter as much as the upfront ones. Regular role-swap testing consumes staff time and sometimes a planned outage window, monitoring the replication lag and health needs to be someone's real responsibility rather than an assumed background task, and managed service add-ons, while they raise the sticker price, often cost less in total than the internal staff time required to build that expertise from scratch. A useful evaluation question is to ask what the total three-year cost looks like across license, infrastructure, bandwidth, and support, since a lower initial quote can hide costs that surface later in the contract.