This is a very good price for a really good gaming console that can play up to PS1. I got it for $40 some time ago (not sure if it was the same seller) and it got delivered in a week without any issue.
Ignore the included microSD card. It's garbage, don't attempt to save the data on it either.
Just get a new microSD card (ideally 128GB+, SanDisk is decent) and then install either
- Done Set 2: https://archive.org/details/done-set-two
- Tiny Best Set: Go!: https://archive.org/details/tiny-best-set-go