Most people spread an outerwear budget across several pieces and then wear one of them. The alternative is to spend the whole amount once and accept a smaller wardrobe. Both grids below make the arithmetic concrete: coats running $1,950 to $3,600, and jackets running $1,210 to $1,395. Roughly speaking, one coat costs between two and three jackets. The right answer depends on your climate and your commute rather than on taste. If you spend real time outdoors in cold weather, the single heavy coat wins because nothing else keeps you warm and nothing else is seen as often. If your winter is mild or mostly spent between buildings and cars, three jackets will get worn far more evenly.

Fabric weight and fibre content, first. A wool or wool-cashmere coat with real weight hangs properly, holds a collar and blocks wind, and you can feel the difference in the hand within seconds. Then the shoulder, which is where tailoring quality either exists or does not, and where alterations are hardest and most expensive. Check the lining is stitched rather than fused, look at whether the pattern matches across the seams, and press the collar to see whether it springs back. Length is a practical choice more than a stylistic one: anything below the knee needs a vent to walk in comfortably. Leather is its own case, since it needs no lining logic but does need conditioning, and a good leather trench outlasts almost anything else here if you keep it out of prolonged rain.

Buy one very good coat and be ruthless about the colour. A camel, navy, black or deep brown coat in a heavy wool will carry ten years of wardrobes; a strong colour or a distinct silhouette will feel dated in three, however beautiful it is now. Jackets are where we would take the risk instead, because they cost less, date faster by design and are easier to replace. What we would avoid is buying a statement coat and a practical coat in the same season, since the practical one always wins and the statement one hangs there reproaching you. If you take one thing away, spend the coat budget on weight and shoulder, and spend the jacket budget on the thing that makes you happy.