Samsung makes good drives but so does Crucial. I wouldn't hesitate to buy either one.
Mx500 is Dram-less but uses your system ram as dram. It also has twice the Endurance rating the Samsung has.
I have Crucial MX500 drives and a Samsung 860 EVO drive. I think your reference to the Endurance is with comparison to the 850 EVO. The endurance, from lowest to highest, of the drives is 850 EVO, MX 500, 860 EVO.
That said, I think you can't go wrong with either - for that big of a price difference, I'd go with the Crucial. That seems like an insane difference in price, usually the 860 EVO and MX 500 are within maybe $10 of each other.