Getting a Mn is 100000x better than any mining rig.

Resale value? Trying to sell a rig of say 5x 280x is impossible. Now one buys. I know, I tried for months when LTC was at much higher price.
Selling parts is a nightmare. Ebay kills any good deal. Then there is paypal.

 If DRK starts to drop below your entry point, it take no longer that 10-15 minutes to liquidate. It took me more than 2 months to sell-off my rig at a stupidly low price.