No way I would spend the money for an M.2 Pro drive with a P6T, just get a decent SSD and consider M.2 when you do a new build. You will notice no difference, not even sure if that board would support it as a boot drive (IIRC way back the PCIe Revo Drives would not boot a P6T), and even if it did it would boot slower than a SATA SSD.
Give them some time and they will get a lot cheaper too. Trust me on that, been buying SSDs since my first Intel X25-M 80GB was around $500.