The PINE A64-LTS alone is $40 + shipping + taxes, so you cannot have a $17 total cost.

I assume that you mean that the card with the switch circuit alone could reach $17, if made in a large quantity.

However, you cannot make a managed switch with that card alone.

If your current cost has been $40 for a card with the switch circuit, adding the PINE A64-LTS + whatever you have paid for shipping and taxes must make the total around $100, exactly like I have said.