Darnell would pay 60 / 30 = <<60/30=2>>2 times the $1 texting charge per month.
He would pay 60 / 20 = <<60/20=3>>3 times the $3 call charge per month.
He would pay 2 * 1 + 3 * 3 = 2 + 9 = $<<2*1+3*3=11>>11 per month on the alternative plan.
Thus, Darnell would pay 12 - 11 = $<<12-11=1>>1 less on the alternative plan.
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