I think for what your getting you would be paying to much right now, Ive seem M11s with Lage uppers ($700 worth of upper) go for $4100. Those cans are normally selling for $150-250 and many guys throw in the can for the cost of the stamp if you look around.
I paid $4500 for a m11 with OEM upper and a Lage Max-11 plus a AWC CQD 3 lug and about 6 or 8 mags.
The complete gun in stock form is worth around $2800-3K
The 2nd upper with bolt is about 150-175
The can is worth around $200
Mags vary but I've bought alot them for under $15
If the seller would pay all the taxes it would be about right but theres $800 worth of transfer taxes there if the gun and the silencer are on F4s out of state.