You know that and I know that, but I don't think a lot of people realise it (certainly not in the flurry of planning). Every chick says "I don't want it to be over the top, I just want it to be more like a party where everyone has fun." Fast forward a few months and the bill includes chair covers, marquee, crockery and cutlery hire, catering, lighting, and the list goes on and on.
One of the few episodes of Friends that I watched was where Chandler and Monica were planning their wedding. Chandler told Monica how much money (cash) he had and she said something like "Now we can go with my Plan A wedding" and Chandler said "We're not spending all my money on one party", to which Monica responded "Don't call my wedding a party!"
It'd be nice to think that this was intended and took as a spoof of the conspicuous consumption that big weddings are, but I suspect that, considering the target audience, there was a lot of nodding all around.