Unless you have a specific reason you need the compute of a desktop, I'd go with a laptop for the mobility. At 550 euro there aren't a lot of great laptops as

Unless you have a specific reason you need the compute of a desktop, I'd go with a laptop for the mobility. At 550 euro there aren't a lot of great laptops as far as I know. It's basically where the 15 inch full HD segment starts. I'd look into refurbished laptops (perhaps second hand) in that price range. Preferably get something with warranty (i.e. lenovo thinkpad, or buisness dell stuff, probably any buisness line).