Those upper control arms are real expensive on 560's. Around $350-375 each! It doesn't take any time to hit $1000 in parts for a good front end rebuild. My understanding is that they redid the front suspension on the 107 when they came out with the 560. Wider track and other inprovements. That doesn't help the prices. $1900 for labor seems a bit steep to me. Even at $100/hr, that's still 19 hours. If you were doing the whole job at once, I would think there would be some times subtracted. For that kind of money, you would be justified in asking (politely) the service writer for a detailed breakdown of the labor charges. May be he saved you money, may be he forgot to reduce some charges. If you paid the bill, it's fair to ask.
I've done engine mounts, subframe mounts, and a tie rod in the past year. Ball joints, upper control arms and the rest probably in next 12 months. Really need to do shocks soon. Love my (wife's) '88.