// Azure Myth 6: Cloud is expensive - Azure MythBuster

The perception that cloud is expensive often stems from comparing on-premises hardware purchase costs against cloud operational spend without accounting for the hidden costs of on-premises: hardware depreciation cycles, power, cooling, physical access control, and network connectivity circuits. A more accurate comparison treats cloud as a leasing model where you pay for what you use and can scale to zero during off-peak hours — something that rarely happens in on-premises environments.

Cost design starts with defining your cost envelope: a fixed budget (e.g., £5,000/month), a variable rate (e.g., cost per visitor or per transaction), or both. This envelope should be treated as a requirement alongside the five pillars of software quality — effectively making cost a sixth pillar. Auto-scaling is central to cost efficiency: VM Scale Sets, App Service, and Azure Functions can scale down to a minimal footprint during quiet periods and scale up automatically before predictable spikes such as TV advertising windows or Black Friday. Choosing the wrong abstraction layer — IaaS when serverless would suffice, or serverless when a fixed-price App Service plan is more predictable — leads directly to the wrong cost envelope. PaaS and serverless options also simplify cost forecasting because spend scales linearly with load, unlike the large step-function capex of on-premises hardware refresh cycles.