I started with a Pi 4 8GB. It was not able to keep my RAID 1 (constantly loosing one of the two drives, degraded when added back). Transcoding of movies, also Jellyfin, just not possible. So I bit the bullet and took some old hardware (i7-4790K, 1070, 16GB RAM, PSU, CPU-Cooler) and bought some more used (SFF case, mini-itx board, Bluray-Drive). The case wasn’t the cheapest (56€), because I wanted one with enough room for 5.25" drive and 4 3.5" HDDs. Finding a mini itx board for such an old platform was hard and cost 120€ (I didn’t sell the ATX board I originally used with the CPU, yet). But now it’s a great system, running 19 containers atm In other words, don’t underestimate the cost of old hardware. You may find a cheaper, used prebuilt somewhere