When I started the game in the second half of 2016 rares trading was the way for starting players who weren't focused on combat to make money quickly. I remember using the map from this thread:
https://forums.frontier.co.uk/showthread.php/223321-Rares-Trading-Metro-Map
and several spreadsheets to plan my routes. It was great. Took me all over the bubble and allowed me to work my way through a Hauler, an Adder, a Cobra, a T-6 and finally an AspX. I was kind of sad when I got my T-7 and could carry enough cargo that short-haul trading earned more per hour.
Now, of course, the Road to Riches offers a starting player ten times the hourly rate once he's made enough to spring for a DSS.
It would take a heck of a buff to enable rares trading to compete with that.
I think that just goes to show how out of date the current game play around rares is...
Good points though!