I'm not necessarily talking about the type or make of fabric, but more about the seam work and the construction. Double sticthing, proper thread count, etc. Listen, noone is going to argue that you dont' know your stuff, you obviously spend some of your time learning the finer points of fashion and I'm sure your textbook knowledge is greater than anyone else here...but, its complete and utter overkill and more or less irrelevant for this particular purpose. Furthermore, your display of knowledge doesn't really serve anyone's purpose in this thread.
Maybe I should qualify my statement: within my pricerange, I know how to pick quality garments. I've spent a little bit of time learning about the clothes that I wear and which brands/designers/makes sell more or less crappy clothers for expensive, and which sell good solid clothing for decently cheap. Just like you said, you'll usually never know where the fabric ame from, so its far more important that the fabric be well construcuted.
But in reality, I'm sure you know (really, not trying to condescend you or anything this is sincere) the most important thing about your suit is fit. I know what fits my personality, and I like to be less conservative/edgy. It's true I've only been on one interview so far, but I'm confident my suit choice is both professional, clean-cut, but will help me stand out a bit. That's really as far as anyone needs to take it with medical school interviews...The interviewer is judging you, not the finer points of fashion pertaninig to your suit.
Okay, you win. But just stay away from sateen. It's practically satin... for shirts. Imagine if they took leather and made bedsheets out of it. I don't know who came up with sateen for shirts but he's probably a dickface.
How sateen shirts were invented:
Boss: Hey Jimmy, we're out of broadcloth, pinpoint, herringbone, and everything else. What are we going to use to make shirts?
Jimmy: I got some sateen and that makes for some nice bedspreads.
Boss: Who is going to buy sateen shirts?
Jimmy: How about we sell to the Americans?
Boss: Jimmy, you are a genius. The Americans will buy anything.
Btw, fashion is all about fads. Style will remain the same for centuries. In the past 100 years, there have only been two major changes to suits: darts and the lapel hole (darts and lapel hole counts as "major" change? considering the conservative nature of suits, yes). Everything else has stayed about the same. I'll say it again: your suit will not just be for interviews. You'll have socials, dances, conferences, etc. Get a good investment and it'll be versatile. That is why I really don't understand the concept of the "interview suit." Is the interview suit sorta like "the motorcycle jacket?": good only while on the motorcycle?
Because of the conservative nature of formal wear, the rules and regulations regarding formal wear are set in stone. Wear a dark shirt to an interview and people will think you are a waiter. There was a previous post about a guy who wanted to know if a black suit, a black shirt, and a silver tie was okay? The answer is no. The black shirt is reserved for white tie events (or if you are at a black tie event, the waiter). Like proper etiquette, proper attire is no longer taught in America. Just an anecdote, Jimmy Carter once kissed the Queen on the lips at a white tie event. She was not happy.
I've worn the suit I've chosen for interviews to weddings, temple, to work, and on dates (fancy jacket only restaurants). I've even ordered thousands of dollars worth of toys with my interview suit (I sell toys as a hobby). I find it offensive that people wear shorts to religious services. That just kills me every time.
Get the wrong suit and you'll be stuck with an "interview suit." Get a good suit and you might just be buried in it if you take care of it.
Btw, what is your price range? Often, people are afraid of going off the beaten path when it comes to buying shirts. They would rather trust the big names (Macy's, Nordstroms) than get something from a startup.
Hillhousetailors.com makes custom shirts with prices similar to Nordstrom. MTM for OTR prices.
Not to mention it is a pain in the ass to iron cheap fabric. Buy good fabric and you'll save lots of time ironing. Cheap fabric will wrinkle on the hanger, not just while being worn.