$600 for a fully rigged modular character model is not particularly expensive. If you were to contract that work out, you’d pay more than that.
Money is the way that our society decides who gets to tell whom what to do with their time and assets. More money, means you can influence more people more of the time. The amount you have to pay has to be equal to the time and assets involved in the work you want done.
As for “nobody wants my $50,” perhaps the problem is that the difference between $50 and $0, when it takes may days or weeks to create the asset, just isn’t material?