You may want to look at a Sig P6. They fit your budget,are extremely well made, feel great in your hand, and will last a lifetime. Parts, such as sights, and magazines are readily available.
If you don't have a browning hi power then you don't have one of the Iconic 9mm pistols ever. Save an extra amount to cover the difference. Spend once cry once.
I wanted to get in before the soon to be issued one word post that states only "GLOCK".
What full size pistols do you have? There's a good chance you can find a sub compact version of them in 9mm.
Thanks for the replies. I definitely don't want a full sized 9 right now, even though a new "shiny" P226 is on the list of pistols (along with a Belgian made Hi-Power) that I'd like to have in the collection. This is just something to fill a current hole that will end up being shot and sold within a year.
The oldest starts college this fall and I've got a bunch of other things that need money thrown at them, so $500 is the top end of the budget.
Edited to add that part of the reason I'm not looking for a full size is that my wife will also be shooting this and she struggled with the grips on my last full size, an SR9.