Mechanic selling a 2013 pruis

I just need some advice, my mechanic friend is offering a 2013 pruis with 288k miles. Yes that is alot but he told me he rebuilt the head gasket, waterpumps, valve timing machine, so pretty much rebuilt the engine he's asking $4900 he said i shouldn't have any issues for another 100k miles should i walk or be considerate of this being a good deal? I just need some advice.