That said I do own a 5S with 16GB. It's tight but I loaded two apps and that works for me since I only use it to run our company app and an occasional second app. It's not my day to day phone which is currently the LG G4.
https://www.amazon.com/Apple-iPhone-5S-Smartphone-Refurbished/dp/B00YD53XKC is 270 and from Apple. For me that was the deal back then.