FWIW - if you can afford a used Arrakis, then you can afford a new Altair - which is half of an Arrakis. Actually a new Altair would have the new berrylium tweeter, as opposed to a series 1 Arrakis. If you didn't realizr it - look at and Altair then an Arrakis and you'll see it is actually half of an Arrakis - same cabinet construction, drivers - just less of them.
Interestingly, the Evolution Acoustics MM3 is designed in the same fashion...tweeter in the middle i think.