Hi guys, this is my first thread after lurking for years (Even from when my dad owned my current 4Runner) and am in love with it. This will be my car for years! Hoping to get to at least 250k from my current 118k miles.

At my last 2 oil changes, dealership has been telling me that I have a left front axle that is leaking oil/grease(?). They are quoting me $879 to replace the whole axle.

Is there anything I should do? Maybe bring it to another mechanic if this is too expensive? Replace both front axles at this point (118k miles)? Do I really have to replace the axle to fix this issue?

If that price is reasonable, I will just do it at dealership but I want to make sure I'm not getting ripped off (in dealership standards).

Last question is... based on pictures below, how severe/time sensitive is this issue?
Thanks everyone!