I think it will be a difficult sell since the SP35 is coming out and is $3600 and runs 5.5th.  I would be interested in buying multiples but i am not interested in paying $0.14/kwh since i get it for way less.  The hosting contract kills it for me since it essentially eliminates the already difficult task of paying for the equipment.  Secondly, If you have 100 units you would have got a significant discount from HashPlex for the amount of kwh you were buying.  Lastly, how long have the units been running, cause if it has only been a month in the contract and you are already wanting to sell, i suspect you have realized that the ROI on $6500 for 4.5th was terrible.
good luck...keith