Just like to add that I've been playing Elite Dangerous for 27 hours now (according to STEAM) and literally every second has been "exploring". I have nothing except the basic discovery scanner, the 500ls-range D-scanner and the rest of my modules are just 1 step up from the loaned ones you start with because I'm saving all my money for better scanning stuff. Oh and I'm only flying a Sidewinder (thought about upgrading to an Eagle but I seem to have become fond and attached to my humble little Sidewinder).
27 hours of this and I've yet to get bored. It's really not about money, I just love going to new systems that I haven't yet been to, seeing how many stars are in that solar system and what type they are, seeing what types of planets are orbiting them and how many, it's all just completely awesome. I haven't done the math (and I won't try because I'm terrible at math) but if I could possibly visit and explore every single one of the 400 billion stars in this game in my lifetime (I estimate I have maybe 40 to 60 years left, depending on various factors of course) then I would.
Today my explorer rank went to scout and I found my first planet with life on. My ultimate goal is to get my name on an entire solar system - the star/s and all the planets and moons. Even if it's only one I'll be happy. And when I've done that I'll carry on exploring because I love it!!!