Returning player curious about PLEXFollow

So, I played EVE many years ago but had to quit due to monetary constraints, I'm thiking of coming back now, but I had a question. Would it be possible for someone to throw up a trial account and using that account make enough ISK to purchase a PLEX to avoid paying the monthly fee entirely? Or would that be too much money to make in too little time?

I'm not sure if you could earn 300ish million ISK in 30 days if it's your first 30 days to buy a PLEX, but what I do is I bought 2 PLEXs to get about 660 million (they sold for 330 at the time) and I'm an investor in-game. I have very high skills in Trading and execute dozens of buy/sell orders daily and while I'm doing that, I can do missions at the same time - combined, it's enough to buy PLEX for ISK and still have money for myself.

Level 4 missions are like 30+ million ISK if you're salvaging and such, and if you can do 15 missions like that a month (or trade like I do since I find missions boring after awhile), you're set for life - you won't be rich, but you won't pay to play.