looking for a mac mini 2023 refurbished but its always out of stock on the Apple website

Refurbished items of any product are always in limited number. Newer models tend to get snatched up very fast so one needs to check daily and when spotted purchase immediately.

As for buying refurbished anywhere else, it is generally a crapshoot as to the quality you will get. Also, direct Apple refurbished Macs come with a full Apple warranty and are eligible for AppleCare+ coverage. Any other source of refurbished Macs will not be eligible for AppleCare+ and the only warranty you get is whatever that seller provides and actually getting warranty repairs from them can be difficult at best.

Yep

As woodmeister50 said. It’s like airline tickets you have to check evey hour for correct price. Some kind of a lottery.

but definitely : keep trying from Apple for the warranties options as a brand new. Unless you find an Apple authorized reseller that can reliably offer the same options, same timeframe.