If you like Fernie and Lake Louise/Sunshine, I should think you'd enjoy the terrain at both Jackson Hole and Telluride.
Fernie is a favorite of ours, and Lake Louise/Sunshine aren't far behind. Yes, JH has some "scare the pants off you" steeps, but there is plenty of other advanced and expert terrain to choose from if you're not into that. What I like about JH is the opportunity to really push your limits and improve your skiing. After skiing at JH, I definitely was a much better skier and it made me feel less initimated by steeps at other resorts. Both resorts also have excellent intermediate terrain in case anyone feels they want to knock it down a notch. Jackson intentionally leaves some of the intermediate terrain ungroomed, and that's lots of fun after you've pushed yourself on the tougher terrain. Both resorts are usually uncrowded because they are a bit off the beaten path, requiring an extra plane leg that many people just don't want to take. If you're like us, that's what makes a resort a "must visit," as we really don't like the crowded resorts.
The towns are very different: Jackson Hole is more "rough and tumble" with a hint of refinement, while Telluride is a very swanky Victorian town. Both are beautiful towns with breathtaking environments. The town of Telluride sits at the bottom of a red-rock desert canyon and on one side of town, the red rock rises toward the sky while on the other side, snow-capped, craggy Alpine granite soars above you. There are several peaks that rise above 14,000 feet, which you can see once you've taken lifts up into the mountains. The entire town is a National Historic District, with brightly painted buildings, and feels very authentic. If you want to visit and ski in an area of the U.S. that offers a huge contrast in environment, this is the place. Jackson Hole, on the other hand, is all about vast open space. Jagged peaks soar out of a narrow flat plain that's sliced by the winding Snake River. Jackson is part of 1.7-million acres of national forest and right next to the Grand Teton National Park. When you stand at the top of the mountain, you are really hit by the feeling of being in the middle of nowhere. (Ever been to Kicking Horse? It feels much like that.) Jackson also has Victorian buildings that have been renovated for coffeehouses, galleries, boutiques and restaurants. There are many ranches in the area, so you'll see real cowboys in town too.
As for cost, they are fairly comparable. You can spend as much or as little as you want on lodging and dining, and have fine experiences at both resorts. Perhaps Jackson has a bit more to choose from on the "lower end" of the price scale because part of their target market is the "ski bum." But overall, I don't think there's a huge difference. The daily ticket price at Telluride is higher, but once you've booked a lodging-and-lift package, you won't notice the difference.
I hope that helps a bit!