Makes sense and does not make sense (as its not a 1:1 comparison)
From my experience, if a guy asks, and has that itch, he will buy it even after asking on the forums
Furthermore, as an absolute cost, what you have worked out for the Nikon system will be true.
So this is the part that 'makes sense'
Ok... its not 1:1
and we can fudge some options around too.
The Pentax has SR, so all the lenses you use will benefit (can't say the same for the Nikon options you listed and the SR lenses for Nikon won't be cheap)
You listed DA55 for Pentax but a 50/1.4 for Nikon.
Why not just get the FA50/1.4 (same price range as the Nikon 50/1.4) or list the Nikon 55/1.4 as well (more ex than the Pentax 55)
In fact, I bet the DA50/1.8 works on FF and is cheaper.
77ltd, is unique, its smaller than that Nikon 50/1.4 and a luxurious all metal build, not to mention other qualities.
Not the same lens compared to the Nikon 85/1.8 (a nice lens); They both have merits, just that they are different.
For now, if you want cheaper and short tele, the DA100/2.8 WR is a really good option.
You already have the DA100 WR, which is even better since you don't even need to buy.
70-200, as suggested above, the Tamron or Sigma can be had for cheap too.
There's also the built in GPS, the AA filter simulator and 4 frame high res option to mention a few things that are likely to be on the Pentax FF.
Then there is the ease of use (bracketing with option to choose how many stops in between; green button; shutter release options; etc)
At least no harm to wait and see what comes imo.