Basic trading its very hard to make profitable and only work if you get above the 30% extra price when buying and the 30% cut when selling. Also take into account fuel and supplies. Which can get pretty harsh...
Open market trading is foolish if you aren't taking heavy advantage of markets that are experiencing disruptions. If you wanted, you could raid their starport to create that disruption. You also should be paying attention to the bar looking for trade deals. Often times there will be an offer to buy or sell goods at a decent price with no tax. Missions which hand you a large amount of goods to deliver somewhere will also create a surplus at the destination when you finish, creating an opportunity to buy back those goods and then sell them again for even more profit.
Zlso i don't know what make space police investoigate your fleet cargo.... sometime i buy 2k drugs and nothing sometime i dont even have illegal stuff and still get transcalled...
Each faction has their own list of illegal goods which you can see on the faction reputation menu. For example, Hegemony will not allow selling of heavy arms or drugs on open market (military will take them though) while Tri-tachyon is basically anything goes. However, if you buy anything on the black market, even if they are normally legal to buy, you could get scanned. If you mouse over the tab for black market, it will tell you your current suspicion level. You can reduce suspicion by buying stuff on the open market. It's just a guideline though. Even with the lowest suspicion level minimal you could still get a scan.
the only ressources that suffer less fromt hose problem are the high price ones or illegal ones(since oyu dont pay the +30% -30% of the normal market)
Usually you will want to focus on those high cost goods. There are situations where you can make a decent profit off low cost goods though. For example, if pirates are raiding Askonia, there is a good chance you can buy all the ore off one of their colonies and then drop it off on one of the planets
in the same system, significantly reducing expenditures.
Hello. Judging from your question, English is not your native language.
The irony.