HiveOS Rig Fee Suggestion

We pay 3$ for each rig if we have over 4 rigs. I have 30 rigs running on HiveOS. So I pay 90$ each month. I want to add more rigs to HiveOS instead of Windows.

3$ sounds good for 12 pcs GPU rigs. (RX470,RX570 and above,GTX1060 6GB, and above.)
But there is a problem if we use a few GPU on a rig or older GPU like GTX1050 2GB, RX550 2GB etc.

is it possible to pay acording to how many GPU on a rig ?
is it possible to pay acording to which type GPU on a rig ?

For example: I have two RX480 8GB. I have to use Windows for these two GPUs. I want to use HiveOS but 3$ for 2 GPUs is so much.

For example: I have 6 GTX1050 2GB. The profit is not good. But i want to use them in HiveOS. But I have to use them in Windows beacuse of the cost.