A couple of folks have posted here about the high cost of a trip to Alaska. I did the trip this summer in my Class B - first time since '68 that I've been back home. Round trip for me was a little over 11,000 miles and my total expenses (gas, camping, food, misc) ran about $5,000. Now I did do a lot of dry camping and for most of my stay in Soldotna I camped for free in a friend's back yard where I had electric and water. And I averaged 17MPG for the entire trip.
Some have mentioned that most of the campgrounds only offer 30amp service. That's true in both Canada and Alaska but shouldn't be much of a problem since you're generally not needing to run multiple A/C units.
The most expensive gas was in the Yukon, but gas prices weren't all that bad in Alaska. Yes it was more expensive, but not nearly as bad as it was when I was growing up there. A good trick is to fill up when you're down to 1/2 tank and use Apps like GasBuddy to find the best places/prices.
Historically the Alcan is usually in better shape for the northbound trip in the Spring than it is for the southbound trip in the Fall. The Summer traffic does tend to beat it up, but it's nowhere nearly as bad nowdays as it was back in the '60s when it was 1,100 miles of gravel. Yeah there are frost heaves and some of them aren't marked, but with practice one can usually spot them in time to slow down. The last 100 miles in the Yukon up to the Alaska border were the worst.
And I did manage to visit all the places I remembered from childhood along with some that I'd never been to before. So in additional to Kenai/Soldotna I did Homer, Hope, Seward, Valdez, Skagway, Haines as well as Los Anchorage and Fairbanks. Saw lots of wildlife and as others have mentioned a lot of it was in Canada - black bear, grizzly, moose, caribou, sheep, bison.
Anyway, don't let talk of high cost scare you from making the trip of a lifetime. WIth care and planning it can be done pretty inexpensively and you'll still have a fantastic time.