this is my experience over time.
1 solo hulk going back and forth in hi-sec.. 4-6 misk/hour
1 hulk in hi-sec with hauling ship (without orca) 8-12 misk/hour about
if you add orca and mindlink to above I think it goes up to 15-19misk/hour about. but thats only with very good skills I think.
in 0.0 and w-space getting at ABC ores a solo hulk can make as much as 40misk/hour on arkanor currently I think.
my current calculations from jita median prices of minerals: (21/09/2010)
this is with a hulk (exhumer lvl 4) and 5 t2 drones t2 crystals. 2x t2 mining upgrades. 10% bonus from mining foreman V
the hulk cycle yield is calculated as 1656 m3
each drone yield 56.25m3 per trip. (drone interfacing IV)
isk per hour rates in mil of isk per hour mining. (isk/m3 value in brackets)
veldspar 8.2 (71)
scordite 8.5 (74)
pyroxeres 9.5 (83)
plagioclase 11.0 (96)
omber 7.7 (67)
kernite 11.9 (104)
jaspet 8.6 (75)
hemorphite 9.1 (80)
hedbergite 10.7 (94)
gneiss 11.1 (97)
dark ochre 12.1 (106)
spodumain 9.0 (81)
crokite 19.9 (178)
bistot 25.4 (227)
arkanor 32.58 (291)
mercoxit is a bit differently..
its worth around 194 isk/m3 currently. But it mines slower.
with a skiff and exhumer lvl 4 mercoxit is worth around 8 misk/hour
3 factors should be included when you decide what to mine:
1. what is available
2. what is worth the most
3. what provides the minerals that I most want (if you gonna build with it)
mostly their is little reason to mine omber.. and if arkanor is available your pretty dumb if you mining anything else.