Well, I found a non-platinum/palladium run that's 3 jumps each way, and pays out 160k per round trip. For now...
I think the part Hitt0r is missing about using a L9 to do the same run he's doing is that he'll either exhaust supply or change the margins by dealing in that kind of volume for any period of time.
I don't actually mind making the same run over and over, if the profit is good. I, too, am after higher level ships. I have my eyes on...well, all of them. I want the Anaconda, but I think it has to follow a logical progression of working your way up the ships. You can't save for an L6 in a Sidewinder. I went Sidewinder -> Hauler -> Cobra -> L6. And I'll do L7 and then L9, and then Anaconda, most likely. Not sure about some of the combat ships. My Cobra is geared for both combat and mining, but maybe I should think about a higher combat-specific ship. Could be fun.
It's kind of ironic. I'm sitting here doing trade runs over and over (and making quite nice coin, thanks...no real complaints), and I'm thinking about it. "To what end?" Well, to what end in any game? I've played Ultima Online, EverQuest, WoW, EVE, and several others. What's the goal in any of them? Reaching for the next skill level, the next spell, the next gear, etc. They're -all- treadmills.
And in the end, you really may as well have an app on your phone which you just get alerts from at random intervals, telling you you've levelled something up. It would technically be the same thing as level progression, balance increases, etc. What would be missing is the response your brain gives by way of pleasurable chemicals when you achieve something. If it's just given to you, it's just "meh". If you worked for something, you feel a reward response.
Half the point is enjoying what you're doing, though. I don't know -why- I'm enjoying running the trade runs. Or mining, when I was doing that (and may again...although it certainly seems less profitable now!) It should feel like work. Sometimes it does (usually -right- after getting a new ship, while trying to gear it and being short on cash), other times it's awesome (usually past the, "Oh damn, -that- needs upgrading to make this even useful!" stage...say 50% into a ship).
But it's just the sci-fi setting, and it feels kind of zen/chill. It's like getting to drive around, without having to go out.

Oh, and in an environment I actually like. And hey, how cool is a fuel scoop. Although, I did the math after a little trial and error (and almost frying my ship to ashes once...326% heat levels...OUCH!). Even if you do a perfect fuel scoop on an L6, the time you waste doing it is actually better taken out of profits from the trading, given a 4T cargo bay in the scoop's place. At least if you've got decent margins, it is on an L6. May not hold true on every ship or with bad margins.
I do plan on getting an Anaconda, then going out exploring. That's sort of my eventual goal, really. Ironically, I found this game while reading a review for "No Man's Sky", which I also plan on getting for PS4.

But yeah, it's the journey. I'm an impatient sort, so I'll about something going too slowly... But if it went any faster, it probably would not trigger the same satisfaction.
Guess it's in how you look at playing, and whether you're an instant-gratification or a, "Let me at the endgame NOW!" type personality, or not.
I do find it funny that I hate the grind of daily work for -work-, but don't have any problems grinding in a game. Go figure. Hell, World of Tanks is much the same...grind, grind, grind for that next vehicle... And I have...and will.
I am thinking this may not be Hitt0r's cup of tea, though. Depends... -Why- are you playing it? I'm a sci-fi nut, so...it has all the reason I need.