In any case just to make it clear, Greece is not selling any of its Type 214 submarines. The first submarine is currently operational. The second submarine is about to enter operational service. The third submarine is about to be officially launched. The fourth submarine will be launched by the time the third submarine completes the acceptance trials.
State-owned Olympic Airlines which was Greece's flag carrier airline used to operate (among other planes) four Airbus A-340s that it leased from the Greek govt. At some point we had to privatize Olympic Airlines. The four aircrafts were thus returned to the Greek govt. The Greek govt had no need of these aircrafts so it's only natural that it tried to sell them as well. It managed to sell two of them to a private investor. The other two are still on sale so if anyone is interested in them (state or person) he's free to buy them.
Other than that Greece has three aircrafts for VIP transport, so that the govt can move around. One of them, an Embaer Legacy 600, is currently on sale.