After activating it then the credit for that only works if you checkout in the mobile app and is just one transaction for ti to show the discount, meaning if you buy less than the amount then you lose the rest in the app and in pc it won't show at all. Had issues figuring out the promo as well...
IMO it is a modified pstv, probably with soldered memory where games reside and a modified vitaOS. The vita is close to end of life, too many issues plus you need to try to lock down the mini so that publishers of one of the 20 games take your deal.
Whats the name of the shelves for the vita games? Being small I assume they don't sag? looks like the small ikea billy cases? Also, you should buy these at least for the visible holes : https://www.ikea.com/us/en/catalog/products/80263568/
I got for $10 each the new ghostbuster and the Batman movie story packs @walm. The rest of the small fun packs that are leftwhere overpriced. They did have starter packs for $12 but only last gen like ps3 was available.