Just bought a 2015 13 inch MacBook Pro for $450! All it needed was a fresh copy of Catalina! This is my first Mac computer by the way. Bought it off eBay.
Used Apple MacBook Air 13.3" Intel Core i7 2.0GHz 8GB RAM 256GB SSD MD846LL/A Laptop OS X Catalina (Used) - Walmart.com
Apple MacBook Pro 13″ Retina Early 2015 Core i7 3.1GHz 8GB 250GB SSD macOS 10.15 Catalina – Refresh Computers Online Marketplace
Identify your MacBook Air model - Apple Support
macOS Catalina Compatible Macs and System Requirements: EveryMac.com
How to use Sidecar and enable it on incompatible Macs in Catalina - AppleToolBox
macOS Catalina problems: how to fix the most common macOS Catalina issues | TechRadar
How well does macOS Catalina run on minimum requirements? - YouTube