Isla Fisher, centre, plays a young woman with a spending habit in the comedy Confessions of a Shopaholic. (Robert Zuckerman/Touchstone Pictures/Jerry Bruckheimer, Inc.)

While visions of economic stimulus packages dance in our heads, along comes Confessions of a Shopaholic, a comedy about reckless consumer spending and crushing personal debt. With the economy in the tank and most people now familiar with the term “subprime mortgage crisis,” the timing couldn’t be better for a satire that eviscerates our fetish for designer brands and our over-reliance on credit cards.

It’s a rom-com fantasy about a woman who buys every clothing item in sight and sinks into massive debt, then finds true love without declaring personal bankruptcy. Talk about a fairy tale.

Sadly, Shopaholic isn’t that film. I guess that’s inevitable, considering the source material. Based on Sophie Kinsella’s best-selling series of frothy “light reads,” it’s a rom-com fantasy about a woman who buys every clothing item in sight and sinks into massive debt, then somehow finds true love without declaring personal bankruptcy. Talk about a fairy tale.

Shopaholic doesn’t go for the jugular in its analysis of our profligate ways. Instead, it lobs puffballs, fearful of alienating its core demographic: women who probably don’t want to renounce their love of labels. (At the advance screening I attended, there was actually a booth set up at the front of the theatre, where free samples of lip balm were being doled out.)

This is pretty much a one-woman show. Isla Fisher plays the titular addict, Rebecca Bloomwood, a journalist who can’t manage her own money — this despite the fact that she spends her days dispensing financial advice in a column for a magazine called Successful Saving. This is the first major starring role for Fisher, who was fantastic as the romantic stalker in Wedding Crashers. In that film, we saw her gift for slapstick as she terrorized Vince Vaughn, and she deploys it again here, especially in a scene where Rebecca battles a fellow shopper over some Gucci boots at a sample sale. Fisher gives it her all, but can’t save the incredibly limp script.

Hugh Dancy, left, stars alongside Isla Fisher in Confessions of a Shopaholic. (Robert Zuckerman/Touchstone Pictures/Jerry Bruckheimer, Inc.)

Everything in this film has been done before. Shades of Hugh Grant in Bridget Jones’ Diary, Rebecca’s editor is a posh Brit who becomes her love interest. Blatantly ripping off Meryl Streep in The Devil Wears Prada, Kristin Scott Thomas is on hand to ham it up as fashion maven Alette Naylor, the dour and demanding editrix at the high-end magazine Rebecca is dying to work for. And, of course, every Fifth Avenue window-shopping scene is derived from the ur-text of this genre, the Magna Carta of Manhattan chick-flicks, Sex and The City.

Director P.J. Hogan has plenty of experience in this world, having helmed Muriel’s Wedding and My Best Friend’s Wedding, two vastly superior movies that look positively profound compared to this fluff. Crushed by a superficial script about our culture’s superficiality, Hogan seems to be on auto-pilot here. A subplot about an inept debt collector trying to track down Rebecca seems to plod on forever. Shopaholic doesn’t even deliver credible fashion-porn – there’s nothing here as visually sumptuous as Carrie Bradshaw’s wedding dress fashion shoot for Vogue in SATC. Rebecca’s quirky design choices sometimes look, well, more Cyndi Lauper than Vivienne Westwood.

The likeable Fisher will probably go on to have a solid career, but in Shopaholic her joke meter is flatlining. Dudley Moore managed to wring some bittersweet laughs out of the subject of alcoholism in the Arthur films but, no matter how frivolous the treatment, addiction is difficult comedy terrain, and requires more deftness than is in evidence here. Shopaholic doesn’t succeed as comedy, romance or designer voyeurism. Like a lot of fashion, it’s just a cheap knockoff.

Confessions of a Shopaholic opens Feb. 13.

Greig Dymond writes about the arts for CBCNews.ca.