Another tip for the day. This one is split into two parts. First, never send out a signal under than 1000 MB. To my knowledge, anything under 1000 will pay less. Second, if your signal is of something other than a planet or asteroid (and that first doesn't apply) don't send it. I believe you won't get paid for signals that could be considered an event or rare. I may be wrong about that one. It may be dependent on what kind of signal it is.
Use your equipment efficiently and you'll find yourself with more money to spend for things you want! Though, this is a lot more helpful late game when you get paid more regardless because of tier 3 processing, it'll still help not use equipment as fast, though, so you aren't spending as much money on things you NEED.