People with intellectual disability are accommodated and cared for in a variety of settings in Australia. Direct care is delivered by a mixture of qualified health professionals (nurses) and unlicenced disability support workers in varying combinations depending on the complexity and chronicity of comorbidities experienced by people with intellectual disability. Although some of these disability services continue to employ registered nurses, the size and specialised education of this workforce is decreasing due to a myriad of policy changes, which has the effect of compromising continuity of care and adverse effects on health outcomes. The objective of this study was to compare the differences on the financial cost of a single case using different models of care with, and without, specialised registered nursing input. The single case had profound intellectual disability and multiple chronic and complex health problems and was cared for by a model that included 24 h registered nurse care and support. Four financial scenarios are presented, and the differences both in terms of actual cost, and potential health outcomes are discussed. This study has set the scene for a large study where health economic data can be compared against multiple cases, across a range of care contexts, in order to advance evidence about which models provide the better health outcomes for people with intellectual disability and associated multiple chronic and complex health problems.