Upgrading pre amp advice.

My first foray into better sound was the Audionet Pre1G3 preamp.  Used it is in your price range.  You will get a taste of the Audionet magic!

You might consider a PS Audio Stellar Gold preamp. A little outside your budget new,  but they often have factory refurbished units that would fall into your price range.  I have one,  and imaging and Soundstage is great.  And those are my hot buttons. Very clean and neutral sound. Has XLR output and input.

@vhond - I recommend the Linear Tube Audio Microzotl preamp. I see there are used ones that you could pick up for $3500 - $4K. 

It's an outstanding preamp. I encourage you to research it here on the forum and with general web searches. It is a combination of the best of tubes with the best of solid state. 

@vhond I have the Benchmark LA4 preamp and can’t fault it. It is brilliant for what it is. I bought an Audio Research Ref 6SE preamp a couple of months ago to see what the hype was all about. The ARC thoroughly impressed me. It brought everything to the table which I thought the Benchmark LA4 “lacked”. Don’t get me wrong, I’m keeping the LA4 for a second system but the ARC is now in my reference system and I can’t see any reason to replace it, ever. To really appreciate what it brings to the table you have to pair it with amps and speakers that are on par. 

Afgree with @ghdprentice , it is likely not worthwhile to change with this budget in mind. Even on the resale market. As a principle I have always waited to go to a meaningful step above. Not only just to hear a significant difference but to also get better value. In the long run it is more satisfying and economical IMHO. In the meantime, I suggest you go audition different preamps at different price points. Good luck in your search.