Military surplus.

I’ve got a great coat from the Carabinieri.

shopgoodwill.com they always have tons of high quality coats.

BIFL? Anything made by Magee’s. Real Donegal Irish tweed (wool). Impeccable quality.

Woolrich. I regularly wear a Woolrich parka bought by my dad in Chicago in 1982. He wore it every winter until 1987, on ski trips four times a year for 13 years, gifted it to me when I moved to the northeast US in 2006, and I've worn it ever since. Aside from popped buttons and mending the cuffs, it's still going strong and warm as ever.

Stick to wool.

The heavier the warmer.

Not a brand, but Austrian loden coats from Tyrol are classic and BIFL.

Search for Navy bridge coat on eBay for surplus. Its a Navy pea coat but longer in length. Any tailor can swap the buttons for like $20 if you aren't a fan of the buttons.

Man i want one now

First picture is the Bulgarian greatcoat, they are rather nice although will need to be aired out because they nearly all where stored with moth deterants which smell a lot. A good wool lanolin agent will help get rid of the rough nature of the wool they used. I have a small collection of military greatcoats, Finish officers greatcoat is one of my nicest if you can even find one for sale. British greatcoat from WW2 is also very nice but those are mostly heavily worn these days. The warmest is a Russian bekasha/tulip sheepskin coat. Not sure if you can even get them anymore because well of recent events but those coats are good to any temperature on Earth or any wind condition.

Polish greatcoats are very similar to British ones but are in better shape generally speaking and cheaper. Any of the European style greatcoats are all pretty good though, Austrian ones are a bit thin but they are still nice.

For new coats this is probably the best value for money you can get if you want a new greatcoat. https://www.varusteleka.com/en/product/sarma-wool-coat/61689

You and me both. Just waiting for my kidney sale to go through!

Or the outlets if you live near one. I just picked up a vintage handmade 100% Cashmere coat for $1.49/lb. Steal.

I've found a couple practically new London Fog trenches in the Charlotte NC area

You must be unaware of what happened to woolrich a few years ago.

Old Woolrich is good. New Woolrich is fast fashion garbage.