If they're not paying you for plasma as an O+ don't do it, unless you specifically have some unusual subtyping thing.
Apheresis plasma as anything but A or AB is just not something blood banks really need that much for transfusions, and industrial use can damn well pay for you for the privelege.
They aren't allowed to pay donors in Australia. There are worries that payment would attract people who shouldn't donate and incentivise them to lie on the qualification form
I am very familiar with the industry. I am telling you that you are being taken advantage of to benefit a for-profit company that your presumably non-profit blood banks sell your donations to.
It's one thing when that's to defray their quite high cost of operating, and they're selling plasma that would otherwise be wasted.
It's another thing when they have you coming in just to con you out of plasma.