price on a retrim depends on many things...leather or vinyl
, basic standard trim or custom one off work, quality of the materials.
my trim is worth about 8-10K including seats that includes alot of custom work and a mix of leather and suede
so i guess for everything excluding the seats probably 4-6K
as for the GTR rear quaters the old ones were cut off and the new ones welded on. the job is almost perfect looks factory for thoes who dont know the car and wat it is/was.