T-Mobile's MetroPCS has revived the popular 4 lines for $100 Family Plan promotion that it ran last September through December. The first line is $40 per month, two lines are $70 per month, three lines are $90 per month, and four lines are $100 per month. Plan prices include all taxes and fees.
Each phone gets the equivalent of MetroPCS' $40 plan which includes unlimited talk and messaging and 500 MB per phone of high speed data. Data is actually unlimited but is throttled to 128 Kbps after 500 MB.
As before the promotion is available at MetroPCS stores only, not online and applies to new lines of service only. You can buy new phones or use your own compatible phones (any T-Mobile phone and most unlocked GSM phones from other carriers). Click here to find a MetroPCS store.