You’re concerned with ongoing costs for fuel and power: The wood pellets used with Traeger grills are more expensive than propane or charcoal. You can expect to spend $1 to $3 per grilling session using wood pellets. Propane is far less expensive to operate in a grill, while charcoal fits somewhere in the middle of the cost range. And beware of cheap pellets from third-party manufacturers that contain softwoods like pine. They burn much faster than hardwoods, so the end cost won’t be that much different because you’ll use more of them. And they can introduce unwanted chemicals and contaminants to your food. You will also have some electrical power costs with these Traeger pellet grills.
We purchased our wood pellet grill (Model TFB57CLB) from Costco in August 2017. It came with one bag of the gourmet blend pellets. We used the Traeger cookbook to try a few different recipes in the fall. Most of these involve a period of smoking followed by a period of grilling. The grill seemed to work fine at first. We used it a couple of times on warmer days in the winter and it had some trouble getting up to the desired heat level. We started using it regularly again in April 2018. I was careful to clean it and check the pellets etc. The smoking feature seemed to work alright, but when I would turn the heat up for grilling, the grill would usually struggle to get much over 225. I would resort to turning it up to 375 or more just to get it to 225 and then often it would sink back down to 180 or 160. I went to the troubleshooting guide on the manufacturer's website and checked all the components, which seemed to be working fine.
***Update: 11/2014: It's been a year now and I still adore this little grill. I've got a kamado and 3 different kettles and this is by far the most convenient and easy to use. The smoke rings this guy puts on a brisket are amazing and the flavor is the perfect balance of wood flavor without overpowering the meat. I've researched about 15 different pellet grills and I still can't find a better value than what this grill offers
Pellet grills preheat quickly, so you can start cooking almost immediately, and the pellets are available in a number of woods, for different smoke flavors. The smoke has a subtle wood-fired flavor with less of the acrid flavor that comes from standard wood or charcoal. For the maximum smoke flavor, it’s best to cook at a temperature lower than 250 degrees, while higher temperatures cook faster with less smoke.