I was thinking of that but is there any real con to that?
As mentioned by Intrinion, the condition of refurbished depends on the reseller. But normally you are able to touch and test run the machine. Some units may come with non-US keyboard so just note when viewing.
Being over 3 years old, normally you can expect the battery to not last longer than an hour. For around another $70-$100, you can get yourself a new one from Unicell.
Specs wise, most of the <$500 range come with 4-8GB RAM, with some sellers using SSD instead of HDD. Ideally go for those with an SSD. Alternatively, you can go for a cheaper one with HDD, buy your own 512GB SSD for $110, clone and swap yourself.
Even the 7 year old X230 with an SSD will run circles against the $700 craptop in daily web browsing and general office use. The only thing the craptop will win is battery life because the CPU uses less power. Though it comes at the significant compromise of multitasking capability.
I can understand your caution about used laptops. I was once in the same position as you. Bought myself a $669 Dell 11" 2-in-1 Inspiron craptop back in 2014 and used it for 3 years at home. It was OK for <5 tabs of Chrome/Firefox. 10 tabs with Word/Excel and it became slower. Once you add playing a background video and a few open PDFs, you'd be waiting for the CPU to catch up most of the time. Bear in mind this was with the HDD already swapped for an SSD. Think that's bad enough? Wait till you get hit with Windows Update running aytomatically in the background and everything slows to a crawl.
That's why I refer to the cheap laptops that appear capable on the skin but powered by the Pentiums & Celerons as craptops.