You can get the enterprise version from crucial for less:
http://www.serversdirect.com/about-us/partners/crucial
3.8TB 5100 is $1650 and that gives you full power protection.
The 5100 series is the enterprise version of the MX300 (and the Micron 1100 series). The MX500 is quite different, with different controller (Silicon Motion, instead of Marvell) and firmware.
And in consumer workloads you get 0 benefit from what the 5100 brings. You get 10 times the endurance (almost definitely overkill for a normal PC), and better power protection. But sacrifice overall performance, power consumption in idle (which is what a normal PC does most of the time), and things like the SLC cache. I know enterprise sounds cool but you're better off with a much cheaper (by ~$400) 4TB Samsung 850 EVO. I moved from a 5100 PRO to an 840 EVO (workstation usage) and I'm pleased with the improvement.
Right tool for the right job I guess.