My friend offered me a Marshall JCM 2000 DSL 50 head and cabinet for $1200. Is this a good deal?

Tell him to lower to around 1000$.

Also, do you even want that amp?
My Gear
-ESP truckster
-Ibby RG 7 string
-Mesa/Boogie Studio Preamp (Mk2C+ mod)
-Mesa/Boogie 50-50 Stereo Poweramp
-Mesa/Boogie Vertical 2x12 (C90 and EVM)
I actually do want it. And I agree I should lower it to 1k. I just found out the cab is the 1960AV one too so that's a plus.