On the subject of mini-PCs spesifically, You can buy Intel Atom / Apollo lake system like Beelink x45 for a similar price on Aliexpress, but it's going to be significantly more performant and comes with real storage options.

The PI kicks ass if you want to play with hardware and actually use it's pins to build robots or whatever, or you want to use it's amazing camera and libraries. For pure compute its not a great deal.