You might think "Gee, that's a waste of electricity" using an entire oven to make toast. Where I live, electricity is under $0.15/kwh. It takes about 3 minutes to toast bread on both sides. That works out to about $0.0105 to make toast. If a toaster costs $20, it would take me about 1904 uses of the toaster to pay for itself, not including the electricity the toaster uses. And that's assuming I'm only make the number of slices the toaster can handle (say, 2 or 4?) and not more in the oven.