Nicad battery memory is a thing of the past (if it existed at all, it's a hot topic). I never bother to drain my nicads and I have some that are several years old and still work just fine.

Nimh cells do have more capacity, but the newest generation of Nicads make it closer to 2x than 3x the capacity. (I have a 900mah AA size nicad pack. The largest Nimh pack I've seen in AA size is 1700). Most AA size packs are 600 or 650mah for Nicads and around 1500 for Nimh. (mah = milliamp hours). (back when I first starting flying, the same size and weight Nicad pack was only 400-450mah. That's roughly a 50% increase in capacity over the years. These aren't your father's Nicads).

Your whole situation sounds really odd. Find another dealer to compare with, if nothing else find someone else in your area to talk to. Products vary a bit country to country, but I really have a hard time believeing that Futaba is selling the 6exa with out batteries in the TX, or no battery in the flight pack.

Just to clarify, Futaba and other companies often sell the Transmitter by itself and also sell the transmitter along with the flight pack. The flight pack has the Receiver (RX), switch, battery, servos, and usually some other stuff like mounting hardware. You should be looking for a TX with flight pack, not a TX-only deal. However, even in the TX-only deals that I've seen, the TX comes with batteries in it. Maybe it's different where you are, but I'm skeptical.