I had to replace all front suspension bushings on my 1990 300TE.
Most of these bushings are relatively inexpensive. I suggest doing all of them. If you have a mixture of worn and non-worn parts, your new parts will just wear faster, and handling/ride will still be sub-par.
Bushings to look at:
sway bar inner/outer $25-40 for parts (oem v.s. non-eom v.s. MB parts)
end tie rod bushings
check the stabilizer shock assembly (shock and bushings, if any)
control arm bushings ** more expensive
strut mounts (big rubber cap thingie where strut bolts to body of car) ** more expensive
Regarding the control arm bushings specifically. The shop will have to remove the entire control arm, and use a mechanical press to punch out the existing bushings, then press in the new bushings. If your mechanic does not own a press, he/she will have to send the control arm out to another shop to have it done.
At that point, it may be cheaper to simply buy new control arms, and have them installed. I don't remember price on the control arms. $140 - $180 ?