I agree. price is the big consideration. I like the NA for simplicity and durability and but having tracked down a few alarm gremlins, I love the alarm story. Everybody got an aftermarket alarm in their new Volvo back in the 80 and 90s but nobody takes in an OLD Volvo to get an alarm, which kills the car then sells it... TWICE. They must have really fried something, The "just a harness" line is a joke. That's like telling the buyer "it just needs a motor" but in this case, while the parts cost about the same, the shop labor time makes this WAY more expensive.

and since it's sold twice without getting fixed, clearly others have found out the same thing.

Tell the seller the main control module alone is over $400 (rebuilt)and my starting offer would be "I'll tow the car off for free.".Then work up from there.

On the other hand,there are some guys on the BB that have raised electrical wiring to an "ART" and could probably fix it over the phone.
Good luck