Favorite phono stage in the $500-$800 range?

If you want tubes a used Allnic H-1200 is tough to beat. I'm running a Rega P9/RB1000-AT-OC9mk2/Allnic H-1200, this set up is stellar when regarding price/performance ratio. On the SS side the Linn Linto(used) just sounds right even if it lacks flexibility.

"04-10-15: Plato
Definitely the Ray Samuels F-117 Nighthawk battery powered unit."

+1 on this suggestion. They appear used on Audiogon occasionally. Very quiet. I owned one and recently sold it to a friend who is very pleased. I upgraded to something much more expensive.

I also think using the build in stage from Rogue is a good suggestion.

Grado PH-1 in nice wooden box cost $500 new (much cheaper if you buy used). I have two in my second system for a long time, but mostly use it for MM/MI. Anyway high gain option also available to use with MC.

Also check Sound Smith phono preamps!

Consider the Vista Audio phono section. Price is below your bottom price, but it performs above your top price.

Another vote for the Jasmine. Performs way above its price point.