For single countries though the Interrail not worth it, or more like make your own research

For example in Hungary we have an unlimited pass for ~53€ a month, valid on all trains and multiple public transport options (almost everything in Budapest included) https://bkk.hu/en/tickets-and-passes/prices/hungary-pass-ful...

Whereas a 3 days in 1 month Interrail pass is 79€ https://www.interrail.com/en/interrail-passes/one-country-pa...