That’s a huge difference $30k, I don’t think taxes in Amsterdam are that high. You really should be comparing the greater Jackson area also, I’m sure salaries in Clinton for a SWE is going to be higher, Jackson is limited to state jobs. My dad was pulling $100k in port Gibson as a systems engineer and that was a couple of decades ago.
Port Gibson is where the state’s only nuclear plant is. Vicksburg also has waterways, but you don’t get many tech job centers in that part of the USA. Clinton was hotter before Worldcom imploded.