I know this is old, and I will not see the relies, if any (perhaps I may). I am a former Military Enlisted. I am now in sales.
I have worked blue collar and now white collar. I am also very big on appearance. Perhaps military persons will notice this more, but we care not so much about what you wear, but how you wear it. personally if you are in sales, the KEY think i look for , is clean pressed SHARP clothes. whether its a dress shirt and slacks, or a polo. any wrinkles are bad. (aside from the daily drive slight wrinkles in the back) but overall (and especially early morning) there should be none. USE STARCH PEOPLE. another thing. creases. military creases but civilians use them too occasionally.
if you have your dry cleaners press your clothes, then you DEF should have no reason not to have them (cost a few bucks extra) AT THE VERY LEAST PRESS THE SLEEVES. have that crisp sharp edge on your sleeves.
better to have the three in the rear as well. but that's just me.
If you have that attention to detail, it shows. WOW he took the extra time JUST to crease his shirt . (watch out for double creasing though. that looks worse than not having creases at all)
that said as well. Fit is more important that the actual clothes. if you have a baggy shirt that poofs out in the back or sides (or folds over on the sides) it doesn't matter if the shirt was 10 dollars or 500 dollars. it looks like you don't care about image, it looks like you are wearing cheap clothes, and looks unprofessional (unacceptable in my book) even relatively cheap clothes that fit perfectly look like their worth so much more. fit really does go such a long way.
you have NO idea until you change that just how much of an effect it really has. shoes being shined etc.
as for what to wear when you go in. most people know you are in a different position than them. most professionals also understand that generally in sales you make commissions, and that tends to relate to better money. going WAY to much and coming in driving a Ferrari, wearing 5K suit and a 50K watch, yeah that may be ok on wall street, but if you sell to people who make tops of 50K a year, that is just too much. that said, the "acceptable" range I believe is actually quite larger than most believe. because its industry based.
if you sell to one industry you wear a step above,. the reason you wear above and not the same or below, is the same reason we are discussing this.
it comes out to say "look at him he makes enough doing this to wear that or to look like that" he must be good at what he does.
its about your attitude more than what you wear. you can come off super nice wearing really nice clothes and people will like you. wear crappy clothes, and be a complete asshole then they won't and don't be "fake" if you prefer something over someone else like a football team, dont just agree with them, be like "nah i prefer so and so" it creates a friendly joking banter that allows you to talk" don't take it too far though. stay away from politics and religion etc.