Alaska cruise: whalewatching tour offered at juneau port?

we will cruise from Anchorage to Vancouver end of May, stopping at Skagway, Juneau and Kitchkan. we are very interested in whalewatching in Juneau. the online offer is at least $120 for 2 hrs on the sea. Is there whalewatching tour offered at port in Juneau, less expensive? is there a lot of choice in terms of tour operator, departing  time etc? Thank you so much.