The short answer to this question is "sometimes." There may be times when a local big box discount store will offer the same toaster oven that is available online at a lower cost. There are,however, more instances where these retail giants are selling a similar toaster oven which costs less but also has a less powerful or efficient heating system or is just constructed out of cheaper materials. The most common area that suffers is insulation. Without adequate insulation, much heat is wasted and the oven exterior gets very hot.
It is commonplace for large manufacturing companies (such as those which produce toaster ovens) to agree to produce a cheaper product for sale only in a specific chain of big box stores such as Walmart or Target. Part of the agreement involves offering a lower than normal price for what may appear to be the same product. To achieve this lower price changes are made. This may involve using lesser heating elements or cheaper insulation.
How can you tell if the toaster oven you see at the store is the same one you've been reading rave reviews about? Check the model number. The toaster oven may look the same and boast all of the same features but if it is truly the same it will have the same model number.