Tasha hit it on the head! We have 4 different washers. T-300s $4.00 (Which hold 2 loads or 20lbs). T-600s $6.50 (Which hold 4 loads or 40lbs). T-900s $7.50 (Which hold 6 loads or 60lbs), and T-1200s $9.00 (Which hold 8 loads or 80lbs). We generally use the rule of thumb to fill the dryers halfway up the glass so the clothes have room to tumble. If you overload and or underload, (yes underload) the dryer they will not work as efficiently.
Use one of the big machines, $7.50 for wash, will cost about $4 to dry, if you split up each load $1 per load for 24 mins. Don't over stuff the dryer and you won't over pay :) hope this helps!
Thanks! Your answer is awaiting moderation.