I'm much in the same situation as op.
Working as an airline pilot I'm away a lot, so playing is limited to when I'm home after kids are in bed.
I bought Elite beta and started to play in summer 2014.
The progress was reasonable in the early stages but for the last year I've been stuck at the Python level.
I have tried to enjoy it and haven't been doing too much grinding. Made it a-rated and upgraded with most engineers.
But from here it seems to take unreasonably too much time to advance to bigger ships, without putting in weeks of grinding only!
And with limited time to play, I don't know if it's worth it.
I have, of course missed all Quince, Rhea and other shortcuts that's been available.
How is that even possible?
If I fit my Python with 280 cargo slots and find a good loop route from eddb.io, I can maybe make 1.4 mcr per roundtrip. Four round trips in an hour gives me 5 millions.
So in order to get 150 million, I would need to grind for 30 hours. Playing a couple of hours a couple of evenings per week, would take me months to get there.
Months of doing boring grinding, instead of enjoying the game, doing different missions, joining with factions, bounty hunting etc.
I have chosen the latter, which is probably one reason that I haven't advanced further. It's a shame Elite isn't rewarding that kind of play enough.
How is that even possible?
Any hints would be appreciated.
Then you have found something I haven't even been close to.
I have never managed more than 5-6 m per hour from trading. On rare occasions I have been close to that with bounty hunting.
According to the right side menu I have a total play time of 6 weeks. That's about 1000 hours. Some of that is beta testing of course. Trade rank is Entrepreneur and combat rank is Dangerous.
Don't you think almost 3 years and 1000 hours of varied playing (not grinding) should be sufficient for more than a Python?