Technically, after the Skype video/audio call is initialized, the Member is charged in the first second with the amount set by the model and afterward, at every 60 seconds.
Example:
Model's Jenna price is $3 per minute:
You call her, in the first second of the call (time 0:01) your account is debited with $3. After 60 seconds (time 1:00) your account is debited another $3.
if the total call time is 3:57 sec, the cost is 4 min x $3 = $12
if the total call time is 4:00 sec, the cost is 5 min x $3 = $15
if the total call time is 4:01 sec, the cost is 5 min x $3 = $15
if the total call time is 4:23 sec, the cost is 5 min x $3 = $15
if the total call time is 4:59 sec, the cost is 5 min x $3 = $15