DPW gets no fees when you send to paypal, commission only incurred when sold thru DPW auction of 3%.
Sending them to Etsy from DPW is an extra unneeded step since you will have your payment processing thru etsy or paypal and I believe it is the same, 3.4%.
Though one pro to doing so if you already have it listed in both DPW & Etsy, is that the checkout process DPW-ETSY will remove it from current sale in etsy and DPW at the same time. Is there another 'pro' to sending to Etsy? Idk.