The normal entry fee is $ 19.50 a car per day. If you camp then there are the camping fees on top of that.
We buy a yearly pass because we are only 4 hours from Jasper and are through the area at least 6 times a year.
For 2017 the entrance fees are waived but you still have to pay for camping.
Most of the RV Parks in Banff and Jasper are already booked for the long weekends this year. Might be some cancellations so always good to check. We have just showed up at Jasper on a long weekend and got into an unserviced site.