The cost of owning a pet turtle can vary depending on the species and size of the turtle, as well as the cost of the initial purchase or adoption fee. On average, a pet turtle can cost anywhere from $20 to $200 or more. The cost of the turtle's enclosure, heat lamp, basking spot, UVB light, and food will also need to be factored in when considering the total cost of owning a pet turtle. Additionally, veterinary care costs, such as regular check-ups and any necessary treatments, should also be taken into account.