It's pre-owned and it's the 2010 model. So yes legit and yes cheap... But you probably wouldn't expect to pay much more than that elsewhere e.g. on eBay or whatever.
There refurbished. All the refurbished parts are used too. Look in some of the pulldown options.. More expensive for new power cord.. new battery.. etc Price is about average for a 3 year old refurb, maybe even slightly high.
www.usedmac.com or www.powermax.com are the best places to get Macs super cheap. I still have the old G5 I bought from usedmac.com with 8GB RAM for under 400.00 a few years ago.
Well if she don't require anything that uses Windows or bootcamp, get her a PPC G4 Powerbook.. They are dirt cheap and can run OS X up til leopard (the first not snow). Can get a nice G4 Powerbook for under $300.00 https://www.usedmac.com/products/apple-powerbook/powerbook-g4 Latest Safari, Firefox etc all still support OS X 10.5 (Leopard), so should be fine for someone not requiring a intel processor.