Put it this way (tower hobbies prices, where skysports are 150$):

1 6XAS + 5 flight packs = 830$, includes

1 computer radio (6 channels)
6 receivers
1 TX battery
6 RX batteries
1 sets of crystals
1 overnight charger
24 servos (bb 3004)
1 servo tray
6 switch harnesses
1 servo extension wire (6")
5 servo extension wires (9")

1 6xas + 5 skysports: = 975$, includes

1 computer radio (6 channels)
5 four-channel radios
6 receivers
6 TX batteries
6 RX batteries
6 sets of crystals
6 overnight chargers
24 servos (bb 3004)
6 servo trays
6 switch harnesses
1 servo extension wire (6")

The difference: 145$ for 5 tx batteries, 5 sets of crystals, 5 overnight, and 5 servo trays more (though you're missing 5 servo extension wires)!

I'm not considering the extra TXs, but think about this, you can sell the 5 skysports on ebay as buddy boxes for 10$ each and get back 50$.

Tell me why anyone bothers with buying Flight packs again?

Here's another even simpler way of looking at it:
Skysport = 150$
Flight Pack + Crystal set = 150$