It is likely that the profit margin on the 250 Pro is higher, with one set of electronics and one case, even if the case is supposedly more expensive to manufacture when compared to the 220 Pro case.
Against the 200, the 250 reportedly sounds warmer and has better timbre (or at least that is the case for 400 vs 800). The idea must be that a prospective buyer will be "encouraged" to purchase the 1000 Pro (with better profit margins compared to 440 Pro) instead of considering a 250 Pro (even if that owner may upgrade to a 1000 Pro in future) should one prefer the warmer sound but could do without the additional power.
Of course, with a dual mono, the future upgrade costs would be higher. All things being equal (no change in casing), more profit from offering two sets of replacement electronics
Still, one does not know if there will be a new casing for the next generation but, dual mono = two new cases to upgrade/part exchange too
Against the 200, the 250 reportedly sounds warmer and has better timbre (or at least that is the case for 400 vs 800). The idea must be that a prospective buyer will be "encouraged" to purchase the 1000 Pro (with better profit margins compared to 440 Pro) instead of considering a 250 Pro (even if that owner may upgrade to a 1000 Pro in future) should one prefer the warmer sound but could do without the additional power.
Of course, with a dual mono, the future upgrade costs would be higher. All things being equal (no change in casing), more profit from offering two sets of replacement electronics
Still, one does not know if there will be a new casing for the next generation but, dual mono = two new cases to upgrade/part exchange too
