Amazon offers the Holmes HEPA-Type Desktop Air Purifier in White, model no. HAP242-NUC, for $29.99. Clip the 20% off coupon on the product page to cut the price to $23.99. Plus, Prime members receive free shipping. (Non-members can spend $35 to receive free shipping; otherwise, shipping costs $10.23.) That's $4 under last month's mention and the lowest total price we could find by $14. It features three speed settings, front and top vents, and uses Holmes AER1 HEPA filters.