This edge cut error is most common one in the modern coins, and 50 lipa would not be an exception. of course, it worth more then usual “correct” one, but% of cut is quite small, so I guess price would be about $10 maximum .
Croatian error coins are quite variable, usually they have errors in letters, extra metal in some parts, rotation errors, and errors like you have. You found a well preserved one, so that is a good sign. However, i would grade it before selling to clear all the doubt, even though these coins are relatively cheap.