Cartridge recommendations?

The Nagaoka MP-110 is in your price range. Have compared it against higher priced Ortofon, Dynavector, Sumlko, Grado, etc. It's a killer....:-)

Needs
High compliance
4-7 g weight
MM or HOMC
easily sourced
replaceable stylus
$100-200
balanced good sound

Nagaoka MP100,110,200 compliance is VERY LOW for a moving permalloy (mm/mi) cartridge! Dynamic Compliance is listed as 6cm/dyne at 100hz, so at 10hz dynamic compliance of this cart is just 10cu which is very low compliance!

If you are looking for high compliance cartridges (as you said) stay away from Nagaoka.

I am very happy with my Goldring 1042 MM cart, switching from an AT one some time back.  I believe it is medium to high compliance.

Compliance is over-rated. I have used high and low compliance carts on my turntable with excellent results with both. While I wouldn't recommend a total mismatch, give various carts a listen if you are able. You will be surprised at the results. Some here follow nothing but stats. A little knowledge with them can be dangerous...lol. :-) 

Also OP, the Nagaoka MP-110 easily meets all of your other requirements including balanced good sound.