Plex prices will seem high, if you just pvp, mine and trade in high sec.
Most of null sec is empty. Venture down and get a clone at any npc station.
Scan for yummy pve and do two or three of them in one sitting. You will have easily made yourself 500m in about an hour.
If you would like to do something else once in a while, scan for yummy hacking sites and easily pull off 250m per site. So four hours of nul sec game time per month and you have your 2b isk.
Why not take a friend and share the yummyness? Or join a nice small corp in null sec?
Just make sure you have a nice pve t2 ship with a good ab and you can tank anything null pve throws at you.
Want extra isk? Drop a mobile tractorbeam in each anomaly and collect it when you are done. The loot can range from 200m to 600m.