Well, I dunno about you but for me, 10LY jump range is more than enough for most jobs with the help of http://www.elitetradingtool.co.uk/. Plus I get a good laugh when I explode some good-for-nothing, small-time vermin with what's literally a flying shipping container.
I thought so too when I began, but apparently more experienced players think that's peanuts. I see people optimizing with nearly 20ly for trade, so, yeah =P
My cobra now jumps 15 and my Adder 22, and it's much more practical.