KNCMiner Titan with 4 cubes. Average hashrate: 300Mh/s - 325MH/s. Completely Stable. Runs for weeks and weeks with no intervention required. Currently making $600/mo (20% return per month). Why am I selling?

I am just tired of having it in my workshop.
GenTarkin's Titan upgrade is installed.
Included:
Four (4) Titan Mining Cubes.
Controller Board with four (4x) xables.
SD Card.
Four (4x) power supplies (all 80 PLUS 'Gold') and all required cabling.
$3000 via Bitcoin or Litecoin. Escrow okay. Sorry, I'm not considering any offers. I dont even know if I want to part with my baby...
Will package it well and ship it insured via Fedex.
Pics on my ebay auction:
http://www.ebay.com/itm/141865837537?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649