I can well afford £70 - I'm going Paintballing tomorrow and am likely to spend that much - but considering that I bought DB about 18 months or so ago and that I've hardly looked at it for at least a year now, I think shelling out £70 for something I'm not likely to use is, yes, expensive.
I'm not saying it's not WORTH it. For someone with the dedication to use it, it's well worth it. But for someone like me who never gets the chance to sit down, design and then write a program, it's not worth it.