You are thinking like a veteran, not like a noob.
Yes, player-generated credits have skyrocketed due to all the exploits, but game-generated credits have (nearly) remained the same for the last 10 years.
A newbie's source of income are game-generated credits, long before he/she ever sells anything to another player.
You don't have an S10 twink, you don't even have a Foreman's twink.
No matter how cheap cities are now, as a newbie you CANNOT afford that. Heck, you probably have trouble buying a yalm!
So, I cannot see ANY realistic scenario where a newbie doc can earn 1 billion credits in 2 months.
As a true newbie, you are probably TL6 in 2 months with sub-par gear/symbiants and maybe 100M to your name.
And even that requires a lot of time and dedication.
1) Because of the low population, finding a babysitter org isn't easy!
Many orgs are just too small these days. Those that aren't, are often focused on endgame content, not helping newbies.
2) For the same reason, finding anything on LFT, other than Ely hecks or Inf mish, isn't easy.
And even that might not be easy if you happen to play during off-peak (which is about 12h a day).
And of course, everything is priced out of range for a newbie.
Not just gear, symbiants and nanos, but also buffs and tradeskills - everybody expects to be paid and every tip takes a big chunk out of your newbie budget.
Yes, there are still a few viable sources of income for newbies.
The best one, in my opinion, is farming basic clothing for AI armor and sell it on shopping bots or GMI.
Of course, since everything is so poorly documented in AO, a newbie might not know about that for many weeks to come.
Yeah sure, the NPE is coming someday and it will be an improvement over Noob Island.
But I'm afraid the NPE will not change any of these fundamental challenges either.