Hello,
Sorry the late response.
Yes, the main factors that I've found are the market sizes given by the population size and the number of production facilities present on the planet. Some facilities simply create resources out of nothing from what I've seen. Other require raw materials, though how its working at the moment in the game I think some of these are created regardless of the raw material available.
Some market conditions have a huge impact on the market, like the Trade Center, Headquarters, Shipbreaking Yard and a few more.
You need to tweak the market conditions of your planets until you get the desired prices really... I'm sure there is probably a more efficient way of doing this but I took the empirical approach and tweaked the planets until I was satisfied with the prices.
I suggest you do this without any mods, at first, and after you've hit the your target prices/material availability add mods one by one and check the market prices.
If they go nuts again, adjust the conditions accordingly. You can even take it a step farther by checking what mods are available and generating the market conditions based on the active mods (though I've not tested this approach yet I'm sure its doable
).
At one point I ran into a snag and the market stabilization was taking forever with after I had activated a lot of mods and SS+, but I don't quite remember how I fixed though (or if i did fix it lol).
Here is a nice Infographic that helped me when I tried tweaking the market.
http://fractalsoftworks.com/forum/index.php?topic=8493.0My market is by no means perfect now, but at least supplies don't cost 1000 credits per unit now.
At any rate I hope this helps.
Cheers.