National Health Service
When the NHS started it turned out to be a lot more expensive (about £179 million in 1947) than expected.  In 1948 it had gone up to £305 million a year.  In 1956 the Guillebaud Report - Enquiry into the Cost of the National Health Service - reported that the costs as a % of GDP had actually gone down. Since 1947 there have been a lot of new valuable but expensive drugs invented.