This code does not seem to require Plus membership. It works on eligible stores as well as a number of private sellers.
E.g.
Sony KD65X9000H (Seconds^) 65" Full Array LED 4K $1396 delivered. out of stock
Sony KD55X9000H (Seconds^) 55" Full Array LED 4K $1049 delivered. out of stock
Sony XR55A80J (Seconds^) 55" BRAVIA XR OLED 4K $1896 delivered. out of stock
Sony ILCE7B (Seconds^) Alpha 7 Full Frame Camera $678.19 delivered.
Offer Period. This offer commences at 10:00am AEDT on 20th December 2021 and is available for a limited time only (“Offer Period”). eBay reserves the right to cancel the offer at any time.
Conditions. This offer entitles you to a Discount off the pre-coupon purchase price (excluding postage costs) on Eligible Items during the Offer Period. Multiple items may be purchased in 5 transactions (up to a maximum of 10 items per transaction).
“Eligible Items” means items listed on eBay.com.au where a link to these terms and conditions and the coupon redemption code SNSBD is found in the item listing, or the item appears in the following URL:
https://www.ebay.com.au/e/coupon-offers/open-s-s-dec21
“Discount” means the amount saved per transaction as set out below:
Save $10 when you spend $100 - $499 in one transaction; or
Save $50 when you spend $500 - $999 in one transaction.
Save $100 when you spend $1000 or more in one transaction;
Redemption. To redeem this offer during the Offer Period, enter the redemption code SNSBD into the redemption code box during checkout . This code cannot be used in conjunction with any other eBay offer, coupon or voucher. You can only use the redemption code 5 times during the Offer Period. The code is provided to you as an eBay User and the limitations on its usage apply on that basis even though you may have registered a number of different eBay User IDs.