I don't know firsthand, but I believe this has an Epson DX7 head, which is basically the same/similar to most current solvent machine heads like the Mutoh 1624x, Mimaki, Roland, etc. They all use "about the same" amount of ink - but as always, the profile you pick, resolution and ink coverage all come in to play. Very easy to figure out cost per ml, just divide total cost by the ml per cartridge and voila! Most OEM inksets will cost between .25 - 35¢/ml on average. If you use a fair amount of ink (we do) go bulk 3rd party and usually can get your costs down to less than .10¢/ml.
Also, not to go off track here, but I think you might be looking at this all wrong. If you're spending $1,000/mo in ink, who cares?!??
You should be making at least $20k in wide format sales/mo if you're spending that much in ink...lol.