The additional system load of downloading and subsequently streaming some video isn't particularly intense, even with real-time transcoding.

The same old 6th-gen i7 desktop rig that I do everything else with also does this job quite well. It's not beefy by any modern measure, and I'd have built it and kept it going (and powered on) even if I never had any intention of running these background processes on it.

The only added hardware expense is one external hard drive (redundancy? hah, no -- not for this). This cost a couple of hundred bucks a several years ago, which is the equivalent of surprisingly few trips to Taco Bell.

One certainly can spend a quite lot on nice kit to accomplish any goal, but that's not an indication of any necessity to do so.

If a film of acceptable quality averages around 2GB (yay h.265), then a 10TB hard drive can hold 5,000 average films.