Best Costco deals to compete with Amazon Prime Day 2025: Top sales ahead of October

October Prime Day (also known as Prime Big Deal Days) is coming up on Oct. 7-8, but Amazon won't be the only place to find discounts. Last year, Costco ran a Member Savings Days event during the same timeframe as October Prime Day, and we may see something similar this year. 

Also: The best October Prime Day deals live now

Costco is a membership-based wholesale retailer. While non-members can shop with a guest account online, only members can access the full savings for the store's sales events (non-members can expect a 5% markup on purchases, and some deals are members-only). Memberships start at $65 a year (and you can sometimes find membership deals through third-party sites).

I'm a commerce editor and, personally, a major Costco fan. I'll help you search through the sales and find the best deals possible ahead of October sales. These are my ...