If you buy stock tanks instead of aquariums, keep things outside to avoid heating costs, use brumation to save money in the winter, or build your own filters to avoid excessive filtration costs, turtle care can be economical. For $80-$150, I can set up a decent red-ear slider habitat outdoors with a 130-gallon stock tank and filtration. Turtles can be a costly hobby if they are kept in aquariums with purchased filters, costing anywhere from $300 to $600.