If you want to bottom feed (like I do), you have to be very patient and have your eye, ear, feelers, etc all out at all times, and be ready to pounce.
I would add you need to know what you're looking at and have a trained eye...
but it sounds like the OP certainly has those bases covered.
Can you get a solid, nice running 66/67 for 8K, yes, but it won't be advertised for very long before someone else gets it first.
While I was walking into the bank with the seller of my 73 Satellite (no rust 54,000 mile original) he got a call from a guy that had looked at it the previous week. The phone guy offered 5K, but the seller, who was already in my bank turned it down for my 4K cash in hand.
I could hear the screaming and cursing through the phone.
Over the next few months I was repeatedly offered 8K, and even 10K.
But a 54,000 mile original with no rust is kinda hard to find, and I still love the car.
My brother (in law) asked me to go with (with my truck and car dolly)
while he looked at a 66 Coronet wagon.
The seller had a 67 GTX that was real nice (not for sale).
The Coronet had sentimental value and was priced too high ($2500) for 225 deluxe model needing some quarter work, so no dice for my bro.
The seller also had a 67 Belvedere II 318 A/C 9 pass wagon in WAY better shape body wise.
(original paint, actually and only floor board damage and related rust)
As we were saying goodbye, ready to leave I asked if he wanted to sell the Bel and if so, how much.
I almost couldn't get my wallet out fast enough when he said "$850"!
Both these were only a few years ago.