Why bother building your DIY one for $70 when you can get a decent air purifier with touch screen, PM2.5 sensor and wireless control for just $100? You'd be pay

Why bother building your DIY one for $70 when you can get a decent air purifier with touch screen, PM2.5 sensor and wireless control for just $100? You'd be paying why more than what you should if your DIY one also have touch screen control, PM2.5 sensor and wireless control - the PM2.5 sensor itself costs $30. I have 4 Xiaomi air purifiers at home in Shanghai, during a highly polluted day (pm2.5 > 150), the in door measurement can be maintained <10 just a few minutes after turning on the Xiaomi air purifier. It has a nice LCD touch display and you can control it remotely using your phone. The price is just $100 each with a preinstalled filter, a replaceable filter that can last for 6 months costs you $40 only. link here - https://item.jd.com/5487565.html https://item.jd.com/5487565.html