There is a big difference in your above options- a tour is not the same as the shuttle. Tours will give you a drive by commentary on downtown Juneau - point out sights, usually stop at Lemon Creek, take you to Alaska Uni and Chaple on the Lake , the independents (only "tours" I recommend for about $20) also usually take you to Douglas Island for a quick photo of your ship across the bay. The shuttle only goes back and forth to Mendenhall and indeed is $10 RT. The tours have about a 20 min stop at Mendenhall but includes the $3 visitor center admission, the shuttles do not. If going to Mendenhall is your interest, there are a range of scheduled ranger programs, good hiking, 3 1/2 mile East Loop trail and 3/4 mile Interpretive trail, get the guide sheet. Be certain to get a shuttle seat as soon as you disembark, MGT has a booth set up at the dock.