Any second-hand business class laptop, i.e. HP Elitebook/Probook/Zbook, Dell Inspiron/Latitude/XPS, or Lenovo Thinkpad.
Businesses tend to get rid of them after 4 years, even if they’re still in good condition. Great bang for your buck and easily repairable if something does end up breaking.
Don’t really know about the US, sorry. eBay might be a good place though.