Bitcoin mining machines, including the Antminer S19 XP+, MicroBT M60S, and Avalon A1466I, have reached their shutdown price due to current mining difficulty and electricity costs of $0.08 per kilowatt-hour, according to Antpool data. The Antminer S21 series is nearing its shutdown price, estimated between $69,000 and $74,000. Additionally, high-hashpower models like the Antminer U3S23H and S23 Hyd have shutdown price points exceeding $44,000.