W124 - which repairs first?

[smharr4]

I had an offer come into my inbox about a free spring checkup at one of my local dealers, so I made an appointment and took my car in earlier today.

An hour later, I had a list of items that they found wrong with the car - my question is, what should I fix first, and what should I fix myself, and what should I leave to the dealer (their quotes in brackets afterwards):

Rear differential L & R axle seals leaking ($700)
Power steering gearbox is seeping
Front flex disc cracking ($235)
steering shock leaking ($190)
oil leak from timing cover/head gasket ($1200)

So, what should I do first?