How do I use Player Auctions for buying gold?

Ok, so I am trying to buy 500m gold for $305. There is this eCheck thing and it is through paypal and it gives 1% off your order. There are no other links just to pay with ONLY paypal without this 1% off.

So, what i am asking is, when I click the eCheck thing, it tells me to make sure to click eCheck payment method or whatever on my paypal. But, when I go to my paypal, there is no option, or atleast i do not see it! Could anyone guide me to it please?

Thank you!

I apologize if this is the wrong section too!