Returning 3er back to owner; how much?

In 01 my father bought a 1982 e21 320is from the original owner and it had around 110,000 mi for $1000.
Soon after he recovered the front seats. He compared them to sitting on a toilet and your butt just sinks in.
Gave the engine a tune up
For christmas this year he gave it to me as a gift since i have been maintaining it for the last 4 years.

At the time it needed around $800-900 in front end repairs
Ball joints
tie rod
four wheel alignment
sway bar bushings

I recently replaced in the last 6-30 months:
radiator
hoses and thermomete
the back shocks
stereo with a 8 spkr setup.
Bavauto ultimate floor mats
K&N air scone
bavauto steering wheel cover
and I have a sunroof wind deflector and a sanden A/C compressor that needs installing

and aside from the front steering issue has not had any issues in almost 18 months.
and it now has around 180k the odo quit working last year

Anyways i recently bought another e36 (i rolled my first one) and unfortunately cannot afford to fix the e21.

The original loved that car and had it for 20 years ever since he bought it brand new right out of college. They are a family friend and we want to give right of first refusal.

Its got all your basic is packaging
Recaro seats
stiffer sway bars
BBS basket weave rims
sunroof
full sized spare
sport steering wheel
5 spd tranny
full tool kit
LSD
it does have A/C
Very very little rust
some on back right tail light cover
but that is pretty much the only place amazingly
and the sun roof needs repainting

I'm looking to sell it for as much as possible so i can pay off my e36 but i also want to maintain a good relationship with the family.

The Questions:
What is it worth in parts?
How much should i sell it to the owner for?
What is this car worth not including the steering issue?
What is the max i could get on the private market?

I have the same kind of car. I love it! I know there are a few for sale on craigslist here in Tucson going for $1500. Check out " German Cars for Sale Blog " too online.. they have a few in top shape 83 320i's as well.. I was selling mine for 1975$ it was then vandalized a few weeks later.. so I still have it.. I'm not sure what I'm going to currently do with it, since I"m also a college student.. I need to find a parts car.. though if this were the case mine would be the parts car.. Not sure any of my information helped.