The fee's will work out to the eBay cost. I've been with Auctiva for over 2 years and the system stays the same. Programming I suppose.
But as a third party lister, whenever the listing goes to eBay, it goes in at the sale price.
When I upload an auction, I can doublecheck on my eBay Seller Account and see that it cost whatever the special listing day cost happens to be.
Best of Luck,
Donna