Do you have a lot of listings- more than 100?
If not you could try just putting the descriptions and the photos on your desktop and setting up a template for the listings of similar items.
Then as you go through the descriptions (with HTML if you have been using it) can quickly be filled in while the category, shipping costs, destinations, Best Offer , price , etc will remain stable from listing to listing.
Item Specifics are something that is peculiar to eBay but is quite important for Google Searches (not for eBay buyers who are using different criteria, I understand).
I find the longest time I spend on a new listing is on making pictures (my stuff is flat so I mostly scan to my desktop) and writing descriptions.
Be sure you don't spend more time making a 'fast and simple' import than you would just making new listings for each item.