Well... what would YOU do?

Okay, so picture yourself as this person. Let's call her a girl. Oh, alright then, a woman. And she's got a very important function to attend , let's call it a wedding. Okay then, it really IS a wedding. And it's a family BIGGIE and it's happening in Tuscany in five weeks' time. These points may be irrelevant. In fact they kinda are. But you get the idea. This woman is going to a wedding in Tuscany. So she has to find something nice to wear. Obviously.
She's a total spaz at knowing what styles suit her, what colours bring out her best features and pretty much everything else there is to know that any normal, sane woman would need to know when choosing a dress. Oh, and it HAS to be chosen during a time that she's not...let's say pre-menstrual or something.
The dress is found. It has taken weeks. No, let's say months of solid searching and husbands-in-waiting (and I MEAN Waiting) and daughters in attendance who'd pretty much want to be anywhere else than with this hair-brained, wild-eyed mother who simply HAS to find this elusive dress that hasn't ever been invented, much less imagined.
But found, it is - eventually and with much sighing and relieved clapping from two very happy co-shoppers.
There's a but. And here it comes...
A week later - today in fact, it is re-found hanging in a different store in her home town (oh yes, she had to drive MILES out of her way to find this dress. It cannot be stressed enough how far and wide this search has spread over the months)and THE DRESS is now proudly screaming 'SALE' at her and ONE HUNDRED POUNDS CHEAPER. (Where's the freaking underline function on this sodding thing?) It really cannot be highlighted, emboldened, italiced, superfonted quite strongly enough as to how much cheaper this dress is now being displayed for - ONE HUNDRED POUNDS!!! Did you get that?!!!
Jeez - what I could DO with a hundred pounds right now!!!!
Needless to say, this woman, let's call her... oh... ME, shall we? came home a shadow of her former self and has been tearing pretty much every available hair from its follicle ever since in search of the answer to the conundrum - "What do I do?"
DO I take it back from whence it came and ask for a refund, nicely? And then drive all the way back home hoping to still find a reduced one in my size?? (can you imagine the absolute nightmare situation if I did this only to find there wasn't one left? Can you? I'd still be looking for another dress come Christmas and I'd have missed the wedding...IT'S IN FIVE WEEKS - did I mention that?!!)
What would YOU DO??
(Oh, and store policy deems any refunds take place within fourteen days of purchase so I only have, like another six days left in which to decide what the f**k I'm going to do!)
Or should a girl just take it on the chin once in a while and just chalk it up to experience? (tra-la-la...)