Sulfur and Phosphorus buttons have been mixed up. You get Phosphorus money from clicking Sulfur and Sulfur from Phosphorus. Also, some of the planets don't show their upgrades, but they do seem to still be making the money.
Fun game, though I think there are a series of bugs that I'm sure others have made aware. I think a few improvements could be made to make each of the mining options selected to their respective planet/moon and have an element/persecond in the planet description so we can have an idea what kind of profit the planete is giving us.
Thanks for your comment.. I've just fixed the prices, now it should be ok, but the old saved game will be lost. I'll add your suggestions to my todo list.
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( see below dev response :) )