The current understanding is that DataTanks cannot be purchased independently. Rather, they are in groups of six per shipping container.
This option for high density mining will be aimed more towards franchisees, who have access to both the funds and electricity to maintain it.
From the DataTank Mining Prospectus
http://www.datatank-mining.com/files/DataTank_Mining_Ops_Prospectus.pdf
You can technically purchase as little as one unit (0.01kW) of a DataTank if you like, so no its not aimed only for big buyers.
[HAVELOCK] DataTank Mining: 1.2MW 3M Novec Immersion Cooled 2PH Mining Container
https://bitcointalksearch.org/topic/datatank-mining-12mw-3m-novec-immersion-cooled-2ph-mining-container-655464