Adam, double-check the info on eBay's page regarding the new fees for Stores sellers. The reduced 11.5% fee rate only applies to Basic stores and above (i.e. Basic, Premium, Anchor, and Enterprise). Starter stores (the lowest tier which costs $4.95/month with a subscription) are charged the same 12.35% fee rate as those without a store subscription.
With a store, Basic level and up:
https://www.ebay.com/help/selling/se...e-fees?id=4809
With a Starter store or without a store:
https://www.ebay.com/help/selling/se...e-fees?id=4822