Well if you play it for a while without investing anything you should be able to get a decent weekly amount.
The energy lack is annoying though.

True, but if you manage your energy well enough it shouldn't be a problem

Instead of building lots of production buildings, you should upgrade existing ones. Saves a lot in energy.

Well duh. I haven't built anything but a goldmine. My current energy is 0 >.<

That's your own fault then, heh!