Depending on what you sell and how much inventory you have, a store can be very cost effective.
In addition, ebay has matured over the last few years from auction heavy to fixed priced listings. It's now about 10% auctions, 90% fixed prices in sports cards.
Seller realize that you get burned more often than rewarded in auctions, since most buyers use sniping strategies/programs. A decade ago there would be bidding wars on almost every card I wanted...and the "flame" icon would note that it was hot. Now only a select few ever get more than a few bids before the last 15 seconds.
A store allows the seller to protect his "investment" and sell at a price he is comfortable with. NO complaints of shilling!
A store listing is a fixed at .10, .05 or .03 versus a non store fixed price listing which is based on your starting price.
You can also offer "best offers"
I don't see a CON for an ebay SELLER.
Fees are a bit higher than auctions 12% versus 9% but the realized price should make up for that difference.