"So we are supposed to pay 2 clerics + 2 range dps 1kk everytime we do an instance which we spam 2-3 per days + using rollback scroll. This is just nonsense. "
You do what you do, this is just a suggestion. 1kk for a TH run is nothing. 1kk in the game itself is nothing. If you spam the instance it's your decision, this suggestion went to players who play without rollback scroll. If clerics don't want to join (which is totally understandable, If I were them I wouldn't bother as well), you need to motivate one. They are using their free time to play, and you essentially asking them to do you free job.
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Edit:
Sorry, I reacted to a previous Cleric.
Changes in team comp is good approach. Get a chanter and bard in your team. If they are not total noobs, most of the frequent, daily instances can be done with them, some of the instances don't even need cleric heal, like KKM. These classes have healings, dispells and shields for a reason. Another approach is to only switch to dps when you doing solo arena, when you have like 6 tickets lined up, I can't see any more reason to switch on DPS stigmas, but if there is, make sure you schedule all on one day. Experiment some. I also using currently this built, and I only switch invincibility mantra to recovery spell and vice versa, for most of the instances it's suitable. Neither full dps, neither full support, it's around 50:50. http://aion.aspirine.su/stigma/?lang=en#bCnashkalaqaBdawepgaaeabgjgof . Everything can be solved with creative thinking.