what is wrong with people

new user so i’m still trying to figure out this game. saw an artist i knew that is VERY unknown and saw they had it priced at 100….i offered them 100 and a rare song and i get this as a response??? is this common on this app or did i just have an odd encounter? i’ve seen a few other people complain about people being greedy but im not sure what more i could have done. i offered what they asked and gave a rare song on top of it. any tips on how to avoid this in the future?