For the 3.5 day one, he might!  Taka has a three-tier pricing policy:
least price for Aussies (or booked in OZ); a higher price for those who
book from the US; and the highest price for the Japanese.

Notice the webpage gives EVERY detail about the vessel and the trips
EXCEPT the prices.  I wouldn't dive on Taka in a 4 share stateroom
even if they PAY me to do it!  :-)  

30 meter (100 ft) boat compared to the 110 ft Aggressors or PhD boats.
30 DIVING passengers on that cattleboat as opposed to 18 or less on
most of the Aggressors.

I did a 4.5 day Cod Hole charter in 2002 (on the old Taka II) in the
best Ensuite cabin (only 1) for $1275 pp.  Our cabin opens into the
dining area (you can literally roll out of bed into the diningroom)
which was standing room only occasionally.

But afterall, we went there for the DIVING.  So all would have been
tolerable if the DIVING itself had not sucked.  It was in November
2002 -- when much of the GBR suffered from coral bleaching and other
oceanic ills that much of the corals were dead -- including the much-
touted Kingdom of Doom.  

I am skeptical that the corals could have made that much of a come
back in two years.  

In a ironic way, for the seemingly inexpensive $1,275 Ensuite we
used (which was far inferior to any of the least expensive cabin
in either the Aggressor or PhD fleets) you DON'T even get what
you paid for (except for having been gouged as Americans, or worse,
if you're Japanese).  14 dives a week is about 14/25 or 14/26
of the number of the dives in one week on a Caribbean liveaboard.

If we equate the 25 dives for $2,000 for a week (on a typical
Aggressor, say), then 14 dives would be 14/25 * 2000 or $1,120
worth of diving (compared to $1,275 charged for the Ensuite)
on much poorer cabin, much much worse food, and worse quality
diving.

In short, the Cairns liveaboards and diving are over-rated, IMHO.

-- Bob.