A cloud invoice and an on-premises infrastructure budget do not necessarily describe the same cost scope. Comparing their totals without examining what is included can create a misleading picture of the options.
Public cloud expenditure may be recorded through provider billing data, while on-premises costs may sit across hardware, software, support and other internal records. Start by deciding which services and cost components belong in the comparison, and use a consistent reporting period.
A hybrid cost model brings the relevant information into a common structure. It can help teams view expenditure by environment and then organise it around the projects, applications or business responsibilities it supports.
The assumptions matter. Record how shared infrastructure is allocated and how assets or services are valued where there is no direct monthly bill. Keep gaps visible so incomplete information is not mistaken for a complete service cost.
With that foundation, technology and finance teams can have a more useful discussion about expenditure, ownership and service choices. The next step is to agree the information and reporting scope needed for your organisation.