It's all relative, i guess.
What's a lot to one person isn't to another, etc.
I agree about the space issue, that's also my main concern... i order my main stuff two months in advance and if it ends up not being that great then i either throw it away or give it to Goodwill as to free up space, also i double up the Comics with one in the front and one in the back using a quality bag/board to really save that extra space. That's also one of the reasons i keep my budget/quantity down in trying to maintain a "quality over quantity" mentality. Usually it's based on the covers first and foremost, because that's what's on display with mine.
I can't get into digital Comics, that would sure save space but there's something preferable about having the physical copy that digital doesn't offer.
But... yeah, i only keep what i consider to be my absolute favorites and best quality for storage/space issues and what not.