Speakers for newbie

thats a good budget-i would rec looking at Tekton Designs speakers. They have lots of good options in your budget

How big is your listening room and will you be using the speakers with a subwoofer?

I'd buy some classic jbls. They are easy to sell, to drive and will give you a lot of bang for the buck. Other upgrades will show well. You can always sell them quickly, at least in my opinion. I bought some 4343's for a wedding and sold them the following week for the same price. Just don't pay too much for them. Usually some old freak has had the cones redone and is selling them at a loss.
Good luck