crimsonstained: "What percentage of the population will think "That looks horrible," if I'm wearing a well-tailored but not great quality suit?"
Very few. Don't sweat it, really. As long as it's 100% wool (or, honestly...94% wool and 6% polyester would be fine, though I have no idea why they'd make one that way) and fits - and you get it pressed once in a while - you'll be doing fine. You can get 100% wool suits for under a hundred bucks at Ross, it's not a high bar to get over, so you will be able to find something perfectly passable at MW. This is a site for complete nerds, their judgement of what's 'barely acceptable' is not the same as that of the general population =)
On the tuxedo thing, and I appreciate you weren't really looking for comments, but to try and explain it briefly...well, a proper classic tuxedo works exactly because it's 'boring': two colours in a very finely balanced contrast. If you wear a tuxedo and then wear a black shirt you destroy the effect of the contrast between black jacket/pants and white shirt; you're now just a giant slab of black. It's not a hideous look, but it's pretty hard to argue that it's not worse than black/white. Coloured ties are difficult to do well for the same reason: you're messing with the simple monochromatic balance.
It's hard to explain, but there's something about the black shirt / white tie combination - and it's not that 'different', C-list actors regularly show up to the Oscars in it and always look awful - that just looks really tacky. Someone else may have the words/expertise to explain it, but all I can say is...it doesn't look good. It just really doesn't.
The funny thing about saying "I'll wear a striped jacket / black shirt / colored tie / chicken feet / whatever and look different!" is that everyone does it. Probably the best way to stand out at a high school prom is to wear an absolutely classic tuxedo, because the chances are quite high it's the one thing no-one else will be wearing. =)
Someone else linked to the Black Tie Guide, and it's really worth reading; there's a lot of 'editorial' in there with some pretty good writing about why a proper tuxedo looks good and why it's so hard to twiddle with it and make it better. The editor has a very...strict...approach - if I was feeling mean I'd say he's a snob, but I'm not and he's awesome so I won't say that, but you get the idea - but it's definitely worth reading and respecting what he has to say.