Lets be perfectly honest here, unless its for work, most of us don't need the top most lens just as we don't need the very fastest computers etc etc.
I love taking photos, and do very little photoshop to tart them up, but do use it to remove dust, shite and neds in the background with their arse out..
I've got a Sigma 105mm fixed lens with I use for macro stuff, 1:2 and its fantastic and was £299 but that's a treat for me..
As you say about amateur photographers, there is a big difference between professional needs and an enjoyable hobby.
I'd get a 2nd hand Nikon or Canon DSLR and a couple of good lens (18-55 and 70-200 kind of thing) and that's all you really need unless you want to blow them up to billboard size or have a deadline in the Sunday Mail.