Help/advice please: 50,000mi 2002 DOA?

[Kathy Forer <kforer@xxxxxxxxxxxxx>]

I'm the original owner of a 1976 maroon bmw 2002 manualT.
It ran 10 years ago, then I let it sit under a tree for another ten.
A local mechanic (who I'll name in private email, I'd like an opinion at
this point) offered to fix it for 1500, all new hoses, tires, new
calipers, simonize. I was to get it today. 

8am call from him saying he'd discovered on final roadtest a steel band
had snapped inside and he opened the car, "stripped it down" and found
rust and bad rubber and now says the car is worthless, good only for
parts. Well, I've put $1000 into it and he says I could get $450 for it. 
It drives but he says it wouldn't be safe. I don't know whether to trust
him or not. He's offering me an 87 Nissan hatchback pulsar (over
100,000mi) in exchange for $1250, down from $1650, and I'd get $450 back
from my purportedly dead bmw.

why couldn't he tell at the beginning this was moribund?  
am I being taken? I'm a city kid, just moving to the semi-burbs, and need
this former car, originally purchased with insurance money from a totaled
(college drivers!) some-kinda-wagon and help from my grandmother. 

I don't know what to do, but would appreciate any and all advice. 
Thank you
kforer@domain.elided

Kathy Forer
Forever Ink 
  Paper Clay Mud Web Design Consulting Production
  http://www.foreverink.com

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