Is it permissible for a wife to engage in buying and selling in a market where men and women intermingle, while she is modestly dressed?

It is permissible for a woman to go to the marketplace for buying and selling if she is in need of it, provided she adheres to the Sharia-compliant dress code and avoids suspicious mingling with men. It is better for her to abstain from it if she is not in need of it.