Because much like a car left in the wrong part of town, it can be stripped and sold for parts for good money.
RPi $20
Power supply = http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=seasonic%20x850&LH_Complete=1&LH_Sold=1&rt=nc&_trksid=p2045573.m1684
Blades = http://www.ebay.com/itm/2-0-2-5MH-s-Gridseed-G-Black-Blade-Chip-Build-your-own-miner-or-Replacement-/251921908088?hash=item3aa7b74178:m:mJ9mDulw0wJ7mTz__eqW6NA
or
http://www.ebay.com/itm/Gridseed-G-Black-Single-hashing-blade-with-cables-/271981226861?hash=item3f53582b6d:g:oB4AAOSw3ydV5yTs
We have been getting $20 to 40 for the USB hub and power distribution box.
Add in about $15 for the aluminum at the scrap yard.
The last 4 we stripped netted about $1550 after eBay fees / PayPal fees / shipping costs. Or close to $400 each.
So that is why they are $200 + S/H
Because taking them apart and selling them piece by piece is tine consuming, but they are still worth money.
-Dave