My wife gave me a blank check for new wheelset. When I will set two new wheels one next to another one and add some kind of triangle at the bottom it should look like a heart-shape.

Very thoughtful.
Currently I have Shimano RS30 and I don't know any better.
I am 145 lbs, CAAD8, looking for aluminum clincher. Not interested in carbon. Though the check is blank I know that anything over $500 will be heart breaking. But I can add a hundred or two from myself.
I went to LBS and they offered me Mavic Elite for $650, or SL for $1000. They both look nice. But I would prefer Elite to stay within budget. The guy said the mavic wheel have less rolling resistance and it will improve performance. No need for the rim tape and I can replace bearings with better ceramic ones in future. Does it make sense?
Since I do not know any better than RS30, what other wheel comparable to Mavic Elite I should look at?
BTW, nashbar has Elite for $400, but they look nothing like the ones from LBS. -- is it a good deal?
And another question, should the wheels have to be new or eBay used ones are fine too?