More like $30 for EACH PIECE. You're talking ~$300 for new D/V's. That's halfway to a rebuilt and calibrated IP. If the DV's are that worn, imagine what the rest of the pumping elements are like?

The OP can try polishing the DV faces, but failing that, it would be wise to find a good used IP or have the one he has rebuilt.

Before getting too carried away, check for air ingress in the fuel system, health of the lift pump, and fuel pump supply pressure.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

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1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]