My wife has dropped more hints about me getting a "project" bike. My 1980 project Alfa sits besides the garage as a testament to a "too hard" basket case.....Italian cars are certainly a challenge.
I want to build up another K and am open to suggestions....prefer 83 to 85 K100. Where can I get enough stuff to get me going? I have been looking on ebay and I am astounded by the bidding frenzy in the last hour before the auction finishes and the ridiculous prices paid.

There was that $250 'complete' motor on eBay from Brissy a week ago...start there. I have seen a few low dollar complete bikes there lately too. Grab one of those plentiful $1500 near-wrecks and have a go at it. Most of them don't sell first time. Do potential buyers fear having to do too much work to make them ridable or are they actually not worth the money asked?

Why an early model? Think of those output shafts with not enough rivets, and the tendency of them to smoke more than later models upon start-up, and that 16 spline driveshaft, and the potential for far more kilometres having been accumulated...it gives me shivers.

My personal ideal would be a 16V K100 or K1100...they've got the goods: Paralever, Motronic, floating disc brakes and accompanying four pot calipers, radial tyres, upgraded front and rear suspension, potential for ABS, and etc.

I was in the same position just over a month ago and tried something different.
Try advertising looking for a project!
I had parted with my '89 LT last November thinking I wanted something modern. Tried 7 or 8 new bikes but couldn't part with the money. You get tighter as you get older.
Wanted another K but like you, couldn't seem to find one at the right price.
So I advertised on 'Gumtree', a free advertising site here in the UK. Within 24 hours I had two responses.
One was an ex police K1100LT with main bearing problems and was, according to the owner, cosmetically challenged.
The other was an '85 RT which had had a lie down and then stored for a couple of years. The new owner intended to hitch it to a side-car but never got around to it. I had saved it from a fate worse than death!
Bottom line. After a few minor repairs, I now have a K100RT with 30,000 miles, running sweet as a nut, in great condition for a total outlay of £450 ($650).
There are pros and cons about both later and earlier K's.
Yes, discovered the smoky engine early on. But find if I remember to park on the centre stand, no smoke at all.
The later K's have ABS, earlier ones don't.
You can argue its something else to go wrong. My LT's ABS never gave any problems, but there again I never used it in anger.
The rivet problem is always at the back of my mind but many early models have done big mileages without any problem.
I have also heard criticism about the 16 valvers not having the same levels of quality in some areas such as master cylinders. More work involved doing the shims as well.
You pays your money and takes your choice.
But I wouldn't be too afraid of an earlier 8 valve, providing the money is right.