well it certainly looks out of place. i had a polytechnic acquaintance who ONLY WORE expensive branded nice clothing. but he always had NO MONEY; simply because he's poor, cared only for how he looked. dined at food courts and looked super out of place with us who were dressed in G2000 and OP back then.
did you know what's the first thought people think of him? "so poor still want to act rich". you can be dressed to the nines but when you stand out from the crowd that's when the criticisms come. be prepared for it.
first impressions don't count when you open your mouth and all that comes out is filth you know. clothes maketh the man, but the mouth will destroy what the clothes portray.
one good example: Ris Low
i have a friend who wears slippers, polo tees and shorts most of the time, and carries a plain-looking sling bag. people dismiss him as some vagrant, but if you look closely, he's wearing LV, Prada, D&G, A|X, Hugo Boss etc from head to toe. going out with him, we don't even need to be well-dressed (i.e. shorts and slippers) to sit at a restaurant at Holland Village with simple drinks that go into the tens of dollars. just open his wallet....and bam! we've got a table.
that being said, true, first impressions count. but not all the time. i can dress in a simple get-up of t-shirt, shorts and slippers. yet i'm always mistaken for being a rich kid (i'm actually very very poor). it's the way you carry yourself and speak that's important as well.
DRESSING WELL is only part of it. how you behave in well-fitting clothes also affects how people look at you.