1995 mercedes-benz c280 misfiring--repair

I recently got my c280 with about 125,000 miles, the previous owner was the original
buyer and took good care if it. In hindsight I recognize that earlier this week I had been
having issues picking up and accelerating after waiting at lights (I thought this was wet-
road related). The other day as I was waiting to turn left and had idled for a while by the
time the arrow turned green. When I stepped on the gas my car (engine? lights were still
on--so not the battery) died. I tried restarting it but had trouble getting my engine to turn
over, by the time I finally did the light was red again and when I tried to accelerate the
engine died again. I could not get my car out of the busy traffic flow and had to have it
towed. The mechanic at the shop my car is at now says oil leaked on my spark plugs
causing my misfiring. He wants to replace the valve cover gasket which is leading oil as
well as my spark plugs wires and boots (apparently my ignition coils look fairly new?). He
also strongly recommends an intake service and fuel injection cleaning(another code
came up on scanner for this?). All in all, with the diagnostic, this will cost just under $1200.
I just want to know if this is reasonable and if I should be looking at anything else as well?