So, I was told that you can play on the test server without the monthly subscription fees. How do you go about that when you purchase the game? Because it asks for your credentials with which you are going to use to pay monthly when you go to buy the game.
There is no guarantee that you can play on the test server in the long term. Its often offline for weeks, and its only active now to test the combat changes. Plus it required subscription too before, they only removed it for now so that the players who have bought the game but was unsatisfied with the combat could test the new combat system and decide if they want to come back. I wouldn't rely on the test server if I were you.
If you buy the client you get 1 month of free play, and nothing guarantees that you can play on the test server after that.