Thank you for taking your time to play my game and for giving me such great feedback - really appriciate!
Money early on is a matter of luck - and depends on how the dices fall regarding the selling prices for Essential resources (I was planning to change prices frequently, but totally forgot about that). A soon as you have unlocked certain Industrial metals or even Platinum metals, you can sell them for much higher prices. The trick is to research common samples only until you have collected more than 50 research points. After that, focus on rare samples (much better chances to unlock Industrial metals) and as soon as you can research exceptional samples, go for them - if you had enough luck to find one until then. Latest when Platinum metals get unlocked, cash is rolling...