In your price range, an active preamp, used, new, SE or balanced, is going to be a difficult find. (I mean one that sounds good.). I'll take a BAT VK3i also if anyone wants to sell me one for around 1k.
If you are willing to give a passive a try, you may want to see if you can find a used Adcom GFP-750. It shouldn't be too much trouble finding one. It has more than 1 input, balanced, SE and a remote. Even though its a passive, it has plenty of features that don't normally come with most units.