PayPal offers a special Micropayments transaction fee which is more affordable for payments under $12 than their standard transaction fee. Once you register for a Micropayments PayPal account (or have PayPal convert your existing PayPal account to Micropayments pricing), here's how you can use that with E-junkie:
If you expect all or most of your order totals to be under $12, for simplicity you may just want to enter the PayPal Email for your Micropayments account in your E-junkie Seller Admin > Edit Profile screen's regular PayPal Email field, so you would receive all your PayPal checkout payments to that account regardless of the order total, and PayPal will apply their Micropayments transaction fee to all payments you receive in that account;
If you expect to have order totals both under and over $12, you can have us send the order totals under $12 to your Micropayments account, while totals over $12 would be sent to your regular PayPal account. In your E-junkie Seller Admin > Edit Profile screen, enter the PayPal Email for your regular PayPal account, then tick the box to Send order totals under $12 to a separate Micropayments account, which will reveal a place to enter enter the PayPal Email for your Micropayments account.