Publish few papers on good or many papers in worse conferences - reputation-wise? A similar question was asked in Having a lot of papers published in unimportant conferences VS very few in good ones?, but my question is only about reputation, so the answers there do not fit my question.

Background

I am working in the field of Machine Learning and for my PhD I need to publish about 3 papers. Before I started my PhD I have been working in industry and am still working in industry half-time (just to earn money, it has nothing to do with my PhD). I do not plan to stay in academia after I finished, but plan to still have connections with academia/research and plan to continue to publish. For my PhD I am only allowed to publish on A1 or A2 conferences (according to Qualis). So for example "SIGKDD" or "NIPS" would be a A1 conference and "ECML-PKDD" or "SIAM DM" is an A2 conference - so they all need to be pretty good, I guess.

Main Question

I would like to know whether what is better regarding reputation: Publish fewer papers on better conferences or more paper on worse conferences. How about better/worse journals?

If you can, please answer for a) the academic world, and b) for the business world.

Clarification

I suspect that publishing on a conference that is worse than A2 is a waste of research time and one might be better of just putting a bit more extra work into the research to publish in at least on a A2 conference.

Additional Question 1: Is that assumption right?

I have only submitted to A2 conferences, so, I do not know how much more work it would be to be able to be accepted to an A1 conference. I guess in both cases you need to do a similar amount of base research work and then some more work which depends on whether it will be A1 or A2 worthy. I would suspect that one might be able to publish twice as many papers (as in "would need half as much research and writing time") if one would only submit to A2 if one would only submit to A1 conferences.

Additional Question 2: Does this rough estimate make sense?

Regarding conference vs journal: We publish mostly in conferences because of the shorter review process. However, after my PhD this might be not so important to me, but instead it will be more important how much work I have to put into it in total (not the length of time from start to completion). It takes me quite a lot of work to shorten all my texts so it fits the page limit. Also, a lot of the negative feedback I get from reviewers is that something was missing, that I had to leave out, because of the page limit. Rejections, of course, cost work (because you need to rewrite text for a different format - we are not counting time I need to additionally spend, because my research not good enough, of course). I think that it might actually less work to write for a journal because of these two points, but I am not sure.

Additional Question 3: Does this makes sense?
I'll suggest that trying to game this out in advance is a mistake. You will miss opportunities and focus on the wrong thing. Do the research. Write the papers and only then decide on an appropriate venue. If you think that a bit of extra effort on a certain paper might help it be accepted in a better conference, then do that. But otherwise send it to an appropriate conference. If you wait a year, trying to improve it, you will get scooped in a hot field. 

You don't want to be the person that only ever did one significant thing and was otherwise unknown in academia. 

First the research, then the papers, then decisions. That is different from not  having a goal, of course. 

But being present in lots of conferences also lets you build your circle of collaborators.