So basically it boils down to whether comments made in a thread should be deemed as a revision to the original terms. If so, this opens the floodgate for abuse.
Essentially yes. As you can see from the reactions in your thread as well as the comment by lemipawa here. You motivated people to invest more time with that comment. People here are eager to do a high amount of work for a little reward. That might be because they have no other options due to lack of education, age or possibilities. I dont know, maybe they dont perceive it as work, dont mind or enjoy it. Be that as it may, you should still honor your word.