$3600 is a GOOD price.
Sticky key fix : $0.00
Headliner : < $100 if you DIY
Headlight glaze : @ $25.00 for a DIY kit.
Valve covers : @ $7.00 for a tube of RTV sealant.

As to the codes, that however does not look good. Looks like something broken in the wiring to me :



There are 5 P0600's listed, but they all seem to do with CAN BUS communication.

HOWEVER ! All that just may be as simple as a single blown fuse. Check all the fuses first.