In other words, bright students, in many cases, are challenged less than they were previously. When challenged less, they learn less. Money spent on gifted programs prevents more important programs from being done. Hence, the cost is minor in the overall budget. Yet, these are often among the first programs cut.
Gifted students are a precious resource.
Money spent on them is an investment in the future which is equal in importance to any other school program. Gifted children burn out early, and develop emotional problems leading to unhappy and friendless adulthoods. Individuals in Terman's study made on average four times as much income as the typical American. Gifted children are physically weak and sickly. This has been documented numerous times starting with Lewis Terman.