hey, Piotr :)
I've edited my earlier comment and that link - now it is working. :)
thanks for pointing that out.
Ok, I'll send another email to this address you gave here
regarding RC costs for each action as I remember I got that information here, scroll down to the section "10. The approximate hours to recharge to 100%", then a bit lower, there is a summary: "In a summary, here are some of my findings:", and there among other things it is mentioned about it:
Posting costed about 2x00M to 4x00M;
...
First comment to other Steemian's post can cost between 1x00M to 2x00M;
Replying to a comment of other's post or your own post can cost between 2x00M to 3x00M;
Replying to a reply to a reply can cost more than 3x00M. I realised the more level of replies you have, the more RC (Mana) is required. I hit 4000M in a particular level 4 or 5 reply.
That's what I've meant by using phrase "cascade replies", usually in Comment section (under post), '1st layer comments' (such as my 1st comment you've replied to) have no dot on the left of it, then replies to comments (such as your reply to my comment) had 1 dot on the left, then reply to reply (as your own reply to your reply here, to my comment) already has 2 dots. in some large conversations can see that some such "cascading replies" may have 5-6 or more dots! and according to the quoted explanation, each such 'next layer' of reply (to reply to reply to reply ...) is MORE costly in RC than previous 'layer'. well, at least if to believe the author of that article. (actually can check it on steemd or siimilar tools). "Plantkon" and / or "Red Fishes" can't afford to make many of such "deep layered" posts (replies to replies to replies) without suffering a significant reduction of their RC! but most likely they are not aware of that. Basially, only "Minnows" and others ("Dolphins", etc) can afford to get engaged in such "Cascading replies" or "deep layered" conversations, because their SP doesn't make them acutely aware on tremendous drain on their RC (aka "Mana").
I have personally experienced that, when I was very low on RC (before I got a delegation). perhaps those who has like about 100 or 200 SP would notice it as much, and those who has over 1000 SP would never even bother about it, unless they make like 1 comment / reply per minute. :D
but people who are with new accounts, very low on SP / RC - certainly can notice that!
that's why it is an essential part of "Education", IMO, to let people know that.
however I have not seen any other people posting about it, only that one author.
if you might find some similar information or perhaps more details about it - please do share! :)