Nobody Told You the Suit Was a System. That's Why Yours Doesn't Fit.
Buy the jacket for the shoulders and the trouser for the break. Everything else is alteration, and alteration is where the money actually goes.

Nobody tells you this when you buy your first genuinely good suit: it's not a purchase, it's a system. It'll look right on the hanger, and the second you put it on your own body it won't — because the hanger was never built like you.
Here's the one rule I actually live by: obsess over the shoulder, then the break. The shoulder's the one thing a tailor can't really fix later — everything else is adjustable. The break is the ankle test: too much fabric pooling reads as inherited, not chosen. Too little reads as outgrown.
The trouser earns the same obsession for a different reason — the break. Too much fabric pooling at the ankle reads as inherited, not chosen. Too little reads as outgrown. The correct break is a narrow window, and it is the detail a well-trained eye clocks before it registers the fabric, the cut, or the color.
Everything else is alteration, and alteration is where the money actually goes.
Here's what nobody tells you at the register: the suit on the rack was never meant to be worn as sold. It's a rough draft in cloth. The real cost isn't the tag — it's the three or four trips back to a tailor after, taking in a waist, softening a sleeve, moving a button half an inch. Half an inch is the whole difference.
I can spot a man who skipped that step from across a room, and so can you. Great fabric in a bad fit reads worse than modest fabric fit right — it just announces money spent without judgment behind it.
The system doesn't stop at the suit. A collar that fights the lapel undoes both pieces. A shoe that fights the break undoes the whole line down from the knee. Buy pieces like they're not talking to each other and your closet fills with expensive things that never once look like they belong together.
Treat the first good suit like tuition, not a purchase. Shoulder first, break second, alteration budget built in from day one — that's the only lesson here that pays you back on every suit you buy after it.