When V4 is already launched, try to fish all cards so you can complete a whole set, but don't say it's easy, sometimes you will get the same card, useless. Therefore, buy the full set to complete your collections quickly, otherwise regret...
I recommend you just buy the whole set or single cards to make your collections much better, making you really complete of V4 collections. Heard that the promotion card from Taiwan is the Killer Whale, will our promotion card will be the Killer Whale?
Fish for them, and if you are lucky to get them all first, hooray for you... but don't sad if you are the last, you still can get much chance for you to do that.