I'm returning to Paris in April 09, just went for the first time in July and loved it! Anyone know what the best (not expensive) department stores or boutiques are? I was able to briefly visit the Chatelet region, but did no shopping other than that.
Don't forget Monoprix! They are everywhere too.
C & A - is inexpensive - best one in Paris is in Montparnasse at Gare Montparnasse.
H & M can be good as well. They are everywhere - including along rue Rennes on the way to C&A
Etam has great buys. So do the stalls outside of the major dept. stores in Paris -Galeries Lafayette and Le Printemps. Wife bought a lot of clothes and accessories there in the little stalls down the sidewalk. Bouchara is near-by 1, rue Lafayette is the best fabrics store in Paris. The high-end Bon Marché on the left bank is lesser known. There are also several shopping centers in Paris and within a 30 mile radius.
I really liked the BHV department store.
There are several good, moderately priced (before the exchange rate anyways) chain clothing stores I would recommend: Koo-Kai, Naf-Naf, Mango, Zara, and Etam.
And of course H&M for the lady on a budget! The location in Les Halles is HUGE.
I don't know if you're looking for items other than clothing, but I would say visit an Yves Rocher store. They have bath, body, and cosmetic products at extremely reasonable prices. And they always have some sort of sale or special deal going on.
More of my favorite stores, the Sephora on Champs Elysee, Bon Marche department store, and the Epicerie (food emporium) across the street. Not exactly cheap, but fabulous.
You will see lots of wonderful small shops wandering the Marais too.