I am able to maintain EBD for about 50.000 dkk a year (using mostly CPH-WAW). I buy GO tickets and upgrade them with plusgrade. If you don't care for points and awards (I don't) then this is cheaper than buying PLUS tickets directly. Basically for 90 000 points that you have to earn you can upgrade 18 segments to PLUS -- so these segments you don't have to pay for a PLUS fare directly.