Je cherche une robe qui me va bien et qui n'est pas trop chère.

Pronunciation: zhuh sher-sh oon rohb kee muh vah bee-ehn ay kee neh pah troh shair

Meaning: I'm looking for a dress that fits me well and isn't too expensive.

This phrase combines two important shopping concerns—fit and budget—and is a natural way to describe your needs to a salesperson in a French boutique.