In reality a 175 or 250, is not sufficient for a dovii, Petenia maybe.
I consider putting a dovii in anything under 500 gal cruel and unusual punishment.
It's not only the space, but the smaller the tank, the more maintenance it requires to keep the cichlid from getting hole in the disease or other maladies they get from living in less than stellar water quality, in small, stressful spaces.
And although finances are the determining factor for many people, its really about how the fish actually thrives in the tank one can afford, not what can I jam into a minimum amount of space, and see if it barely survives.