Just offering an opinion, but I think you are going to be hard pressed to find a "business class" machine in that price range.
You may wish to consider getting a cheap laptop and a good backup drive and backup often.
When the cheap laptop breaks, recycle it and buy a new one.
I know it sounds bad. But I don't think you'll receive any value in buying a $500 laptop PC versus buying a $300 laptop PC.
Another option may be to look a refurbished Dell Lattitude. You can often find online sellers selling these in the $300 range.
I've been researching various laptop options for several family members recently and I've come to the conclusion that PC (Windows) based laptops are throw away devices.
I am the type of person that likes to buy quality items that last. But when it comes to Windows base PC's, I just can't see the point in doing so.