Lowes offers Broan-NuTone 2-Sone 50-CFM White Bathroom Ventilator Fan (ENERGY STAR Certified) for $21.96 

Product Description:
The Broan-NuTone® Energy Star bathroom exhaust fan is a versatile, compact, and economical ventilation solution. Designed for easy installation, this fan can be installed in just 10 minutes without the need for attic access or drywall cutting. Featuring a louvered grille, galvanized steel housing, and double-strength mounting flanges, it delivers powerful ventilation performance at 2.0 sones, helping to prevent mold and mildew. Additionally, the fan includes a removable motor assembly and a plug-in, permanently lubricated motor for easy service and cleaning.