Prices on reconditioning

[iifunky]

Hi guys and gals

I was wondering so as not to get ripped off what the average costs on an e46 323ci or 325ci are for:
reconditioning the:

Steering rack- play on steering ?
diff; have a whine? car seems sluggish
gearbox- occasional non smooth gearchanging

are there any shops you would recommend who can do this; car is off motor plan? i do have warranty so they need to be Rmi approved.

thanks