without wishing to put a dampner on this, what makes you want a D80?
What i mean is if you are really new to this, just sell the 18-55 and get the 18-70 if you want a bit more length, not that there is really anything wrong with the 18-55, and practice.
The D40 is a better imaging device to the D80, its got better noise control, newer processing and is not worth selling...
Amazon do the D40 kit for £220 new, so with a broken flash you would be lucky to see over £100 for it.
Keep the Camera, buy the book, shoot, learn, then buy a D90 when you are ready.