If all you are doing is surfing the internet, especially from the couch, would you consider a tablet (iPad or Android tablet) instead?
If you are set on a full computer, then a refurbished MacBook Air can be had for under a thousand. Or the corresponding sized Windows Machine probably could be had for a couple hundred less than that.
I've got a Dell Inspiron 2200. Kinda old. It served me well for years. Needs a power cord and probably some tuning but for $200 you can't really go wrong
My buddy deals with old laptops. Cheap like under $100 cheap. If you're cool with Windows 7 I'm sure he's got something that'll work for ya. He has some with Windows 10 too I'm sure.