Looks like they will be having upgraded model of L3 soon. 2xL3 basically 4 hashboards, but at bit lower price than 2 units.
I must say I never had seen the L3 in the online shop...
Because they seem incredibly profitable. Since there are no powerful miners in altcoin mining business like bitcoin these are one of the best by the looks of it.
I never used myself so I cannot say anything personally but that is just why people buy it and its always out of stock. It would be wack to find one and purchase it but it gets sold in bulk to some high buyers I assume.