Isn’t shopping online à la eBay, Craigslist or Kijiji a bit cheap? If I buy things at a discount/dollar/department store, won’t people consider it (*gasp*) tacky?

 
Offbeat Bride posted a great article on this very topic. The short and simple answer is: for pretty much anything you can insert into that sentence, the answer is YES.
 

Tacky
Pronunciation: \tak-ee\
Function: adjective, tack-i-er, tack-i-est.
Etymology: Americanism; appar. identical with earlier tack(e)y small horse, pony, poor farmer; of obscure orig.
Date: 1880-85
1. not tasteful or fashionable; dowdy.
2. shabby in appearance; shoddy: a tacky, jerry-built housing development.
3. crass; cheaply vulgar; tasteless; crude.
4. gaudy; flashy; showy.

What most people fail to realize is that you can spend all the money in the world on a wedding… and it can still be the tackiest event ever staged. Allow me to rest my case with the following link.

 
Money and taste do not always go hand in hand. The thing is – the T word gets bandied around far too often, when what’s really meant (for the most part… and, clearly, there WILL be exceptions) is clichéd.
 
Well, of COURSE your wedding is going to be clichéd. You’re planning to stand in a big white (or pink, or red, or whatever colour suits your fancy) dress in front of all your friends and family, surrounded by flowers & tulle, fairy lights and glitter (see? The road to Tacky can often be quite short), to promise to devote the rest of your life to another human being in a ceremony that’s already been done millions of times by millions of people. So originality isn’t really something that’s easy to come by. And why should you kill yourself trying to have the most unique wedding of all time. There’s nothing wrong with taking the basics and adding a few of your own flourishes. And the fact is: it will be the only wedding ever to star You & Your Leading Man/Woman… that alone will make your wedding an original. And that, in and of itself, precludes it from being clichéd and/or tacky. Hopefully.
 
But there are no rules that say you MUST buy your wedding favours/ decorations / shoes / jewelry (this really is a list that can continue on for days) at Le Fancy Pants Bridal Boutique Of Wedding Wankery. You’re welcome to, if you actually enjoy the idea of paying WAY more than you need to on items you’re going to use once.
 
It’s a wedding. It’s a ritual. Rituals by their very nature are done to death (yes, I do realize that can be taken quite literally). Something that’s done to death becomes a cliché… and from cliché it’s a quick jaunt to tacky. Much like beauty: tacky really is in the eye of the beholder.
 
As far as I’m concerned, the only truly heinous and unwavering moments deserving of the Tacky Scarlet Letter are the following: Including registry information in an invitation; Requesting, outright, to be given cash gifts only; and Dollar Dances (or any variation on that theme).
 
Everything beyond that is open for interpretation. Because, although, an idea itself might sound tacky – it’s the execution of said idea that really counts. And there is a point where the whole “is it tacky” question really becomes a case of good ‘ol unadulterated snobbery.
 
So if shopping on eBay or at your local Dollar Store (hey – they have some incredibly pretty trinkets for decorating… on which I’ll elaborate at another time) is what makes you (and, more importantly, your budget) comfortable,  I say have at it. Chances are, your guests will be none the wiser – unless you’ve got a foghorn in place of a voice box, like me, and like to share everything… with everyone. (What can I say? I have no shame. I’ve made my peace.)
 
And if anyone is tactless enough to have a problem with where you’ve purchased your table decorations or how much you’ve paid for your favours & invitations… screw ‘em. Seriously – do you honestly have time to waste caring about what someone with their head that far up their own arse really thinks? They likely spent 4 times as much as you did for their own wedding… and didn’t have nearly as much fun.
 
[Note: the author wishes to let it be known that she fully expects aspects of her own wedding to be brandished with the Tacky wand. She also wishes to let it be known that she’s totally cool with that.]