If you run it 24/7 on a dedicated desktop with decent idle (i.e. no high power video card, low power CPU), it likely uses ~ 50W average. That gives an estimate of 0.05kW24hr30 = 36kWh, which would be in the range of $12/month at current australian electricity prices. If you have bad idle power usage (or somehow mostly active not idle), maybe you'd be looking at twice that. But for OP who was spending $xxx/month on subscriptions, it's a pretty negligible cost. If you really want to save this too, raspPi can do a lot of home server needs nowadays