We did this activity as a prebooked Juneau excursion while on a Holland America Line Alaskan cruise. Price (about USD120) was the same whether booked through the cruise line or direct with the company.
It was a really good afternoon. We were met at the wharf and taken by bus to the bay where we kayaked, with an entertaining commentary on the way. Very slick operation getting everyone kitted up in boots, life jackets and spray skirts, then down to the beach where the kayaks were waiting. We were split up in to three groups of five double kayaks and off we went. Our leader, Brian, was friendly, knowledgeable and informative. Kayaking experience across the group was mixed but Brian kept everyone together as we paddled a triangular course across the bay and back - probably about 1.5 - 2 hours on the water.
The view across the bay to the Glacier was cool, although conditions were a little hazy from the smoke of wildfires burning further north.
A highlight was seeing bald eagles up close. We saw the birds on navigation signs and sand bars in the bay and got very close to them.
Then it was a bus trip back to the wharf on schedule.
Highly recommended activity and operator.