You actually can use a minipc. Minisforum has their NAB series and those have a slot in their internals for an SSD and they have an NVME slot in the motherboard. I found a NAB9 with an NVME, SSD, and 16GB of ram for around $310. So I would look for used NAB6s (cheaper than NAB9) on EBay. You should find some for under 300 with the Data SSD and NVME.
You actually can use a minipc. Minisforum has their NAB series and those have a slot in their internals for an SSD and they have an NVME slot in the motherboard. I found a NAB9 with an NVME, SSD, and 16GB of ram for around $310. So I would look for used NAB6s (cheaper than NAB9) on EBay. You should find some for under 300 with the Data SSD and NVME.