Its expensive because it was only printed in Alpha , Beta , Unlimited , and an old From the Vault set
Casting a 1/1 and attacking the next turn as a 3/2 flying is back-breaking, especially on the blind flip, while you ride the flier to victory using counterspells and bounce spells
The remaining two digits are simply the national code for the country of origin, in this case, Hong Kong
To be honest it's too complicated for me to explain completely here, but if you want to know more you can find out all about it on the official Pokmon website
Additionally, if players want to take their deck to an official event, they'll need to verify which cards are legal as part of the active rotation and which are banned.
ones that don't affect base power and/or toughness) will apply after its base power and toughness are set, regardless of the order those effects were created