I realize everones experiences are different, but here is my experiences so far after a summer on the Rock.
While the higher end animals (dragons mostly) dont drop any high markup (200+%) items they do drop good markup (130-180%) in 50% of the globals and minis (30ped or more) the other 50% of globals consist of axes (101-115%) or oils.
Dragon hides and Zombie legs are used in the new blueprints so will also demand some markup.
It seems that ESIs drop a little more frequently here than on calypso even from low level mobs, though I haven't had much luck getting them, I have bought them off of dragon hunters and noobs alike.
I have never been one to chase the gamble of rare items, but instead seek consistant good markup returns, so for my play style Rocktropia fits pretty well.
The main issue is that the economy is very young and fragile on Rocktropia, most loot still needs to be sold on Calypso. Also with a lack of crafters you need to either
1. Have uber unlimited gear.
2. Bring enough guns to last an entire trip.
3. Be willing to pay a % or 2 over markup for them from a trader such as myself.
The same goes with selling things, you can sell most stuff, but it will be at a lower % that what you could get on caly, since the trader needs to pay for the transportation costs to sell it.
None of this should be an issue though for a higher end player with a bank roll.
If you bring enough gear to cycle 10,000ped on untaxed areas, then the 80 ped travel fee would be the equivelant of hunting on a 0.8% taxed land area.
Its not for everyone, but I like it here. If you do intend on visiting for an extended time, let me know and I will try to stock anything you need while you are here.