The most comprehensive and detailed cost-effectiveness study is by Simon (2011) in the United States who examined four early literacy programs that the WWC had determined showed evidence of effectiveness: Accelerated Reader; Class wide Peer Tutoring; Reading Recovery; and Success for All. The effect sizes for Reading Recovery are substantially larger than the other three programs on each outcome measure considered in her study. Simon put considerable effort into estimating the costs of the programs, including the use of teacher time; such detail has generally been lacking in the other research.

The report in the UK, Every Child a Chance Trust (2009). The long term costs of literacy difficulties (2009) details the cost savings that would accrue to the public purse by the system-wide implementation of Reading Recovery in England and Wales.
ECC Trust lit report 2nd year

In Measuring the Cost of Reading Recovery: A Practical Approach, the author explores how to estimate cost-effectiveness and educational outcomes of Reading Recovery considering retention, remediation, special education, and early intervention. (Gomez 2002)
JRR Fall 2002.FINAL