I don't see how the threshold for GST would personally affect the amount of money you get.. because generally the supplier of the good or service passes the cost onto the consumer of the good or service?? All it would mean is that you actually have to register. (Unless you are concerned that passing on the cost of the GST will damage the relationship/discourage them from using your good or service in the future, in which case, I understand the concern).

And if you register, but don't make that much money, you can claim it back I think.