Findings. Hospital costs by age, 2010. In 2010, the average cost per hospital stay was $9,700 and the aggregate cost for all hospital stays totaled $375.9 billion. Figures 1 and 2 show the distribution of aggregate hospital costs and stays by age and the average hospital cost per stay by age, respectively.ggregate hospital costs in 2010. The cost per stay for 5 principal diagnoses was approximately double the average cost per stay in 2010. ($9,700): septicemia ($18,400), complication of device ($17,600), acute myocardial infarction ($18,200), respiratory failure ($22,300), and intracranial injury ($18,000).