In 2019 my Department spent in the region of €125 million on the 890 schools participating in the programme and serving in excess of 185,000 children. The full list of supports available to DEIS schools is available on my Department's website at the following link
https://www.education.ie/en/Schools-Colleges/Services/DEISdelivering-Equality-of-Opportunity-in-Schools-/deis-supports-to-deis-schools-effective-from-2017-2018-school-year.pdf
A 20% increase in this current level of funding would cost in the order of €25million for a full school year.
Further expenditure on the DEIS programme is also incurred by the Department of Employment Affairs and Social Protection on the School Meals Programme and the Department of Children and Youth Affairs on the School Completion Programme.