STW was a great online game and perhaps, with those old players one could argue it would be worth paying. I played STW a lot.

MTW was a smooth online experience, however they screwed that game with supposed patch 'fixes'. Spears were rendered usless and by v2.01 it was all cav/sword armies and boring tactical play. I did not see anything remotely worth paying for after v1.0.

RTW was a complete mess and none of the patches released could sort it out. The MP community voted with its feet and left. A very large percentage of battles were ruined by idiots, the lobby chat was even blocked due to the infantile behaviour. The worst experience of the series and definitely not worth paying for.

M2TW is a brand new title and already there are many issues. Why would anyone pay? Sure, if the server was smooth and flawless, allowing 4v4 with no problem but it isn't.
It's been six years since STW, there appears to still be a problem providing decent MP. The last thing I would do right now is start paying for this poor service. The game would need to be tactically superb and tightly balanced which it is not. I would give up on MP altogether before paying for it in it's current state.
In short my answer is a definitive no

.......Orda