The Lord Street facility was estimated to cost $6.7million in 2015/14 with the 2015 State Government Budget released earlier this month revealing it would cost $8.47 million to build and $3.9 million to operate annually.
The State Government centre was designed to house up to 10 people with intellectual or cognitive disabilities who are charged with criminal offences but unfit to plead or stand trial.
Bassendean MLA Dave Kelly said the funding for the centre was in stark contrast to funding cuts imposed on most schools including the two closest to the centre, Kiara College and Lockridge Primary School.
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READ NOW"To have it cost over $8 million to build with nearly $4 million each year to run is quite a shock to people, especially when the centre will have at most 10 inmates," he said.
"And all this is happening while the local schools have had to reduce staff to cope with State Government funding cuts, both Kiara College and Lockridge Primary School have had significant funding cuts since 2013."
Education Minister Peter Collier said claims of funding cuts for schools were wrong.
"In their figures, 2013 data includes what are now called targeted initiatives (for example Universal Access, Vocational Education and Training), operational response allocations and regional allocations, while 2015 figures don't," he said.
"In addition, there are a range of other factors, such as the allocation of further disability allocations throughout the course of 2015 that make this type of comparison incredibly misleading.
"Taking these points into account equates to an extra $748 per student in 2015.
"By the end of this year, 2015 per-student funding is expected to be $10,676; this is far more than the $9698 claimed."
Disability Services Minister Helen Morton said a portion of the operation cost would go towards a prison in-reach service to help people with disability in prison to re-integrate into the community.
"The centre will be staffed 24 hours a day, seven days a week " in contrast to school hours " and has been designed to provide a secure and therapeutic environment which supports individuals" needs and develop important life skills," she said.
The centre is expected to open in July.