RAID 1 (Mirroring and Duplexing) Comparing mirroring and duplexing Mirroring is the simplest method of avoiding data loss when a single disk fails. During writes, data is sent to both disks. During reads, different data can be read from both disks, which provides good read Performance. Duplexing is another form of keeping a copy of data. Where mirroring uses a single controller, duplexing can also handle a controller failure. Duplexing requires an operating system that supports RAID 1.
This site says cost of tiling per square metre is between $95 and $170 psm for floor tiles and $90 and $160 for wall tiles. Those prices include tiles so take $30 psm off those.
Expect to pay in the region of: 1  $45 to $60 per square metre for concrete pavers. 2  $40 to $70 per square metre for limestone pavers. 3  $40 to more than $75 per square metre for quartzite pavers.  $70 to $90 for brick 1  pavers. $75 to $100 per square metre for granite, travertine and flagstone pavers.