It depends on the turtle/tortoise
honestly, don't get one because if it gets sick or hurt how the hell are you supposed to pay the vet bills? You have to think of all of the costs of a pet when getting it, not just food, lighting and heating.
If you still are going to get one, get leopard tortoise BUT PLEASE do NOT put it in a tank, turtles and tortoises never realize there is a wall there and it's just a miserable life scratching at the glass.
Why a tortoise, well because for a turtle, you're going to need a pond, and with a pond you're going to need a constant water flow/water changes, water filters and heaters.
Plus it's a huge pain.
Most turtles you buy in pet stores start off small but get large fast and cannot be kept in a tank, bowl, or whatever.
You're looking to pay thousands as the turtles reaches adulthood.
Both turtles and tortoises are lifetime pets, they can possibly outlive you, so owning one should not be taken lightly.
For a tortoise, you can go fancy, or you can go cheap.
Depending on where you live, you can have an indoor or outdoor enclosure.
For an outdoor tortoise you don't need a UV light, but keeping the tortoise warm, which is just as important can be difficult.
Enclosure (once again please do not keep it in a tank) can be cheap or fancy, many keep their tortoises in kiddy pools which run around $20 - $30
Their diet is veggie based, so you can expect $10- $30 a week on food, depending on what you feed it
Don't forget the $3 - $5 calcium supplements (they last a while, though)
UV lights are important, too many owners don't think this is necessary.
$20 for the fixture
$30 - $40 for the bulb which has to be replaced every 6 months whether or not it's working or not.
Basking fixture $7
Basking light $7 (will probably go out every few months)
under enclosure heating pad $15 - $30
If your leopard tortoise is only housed indoors at night or during brief winter periods, newspaper works as a substrate. For a permanent indoor enclosure, substrates such as grass clippings, peat moss or potting soil work well. Also include different microclimates, including a warm, moist hide box and dry area with a basking light.
So the minimum to get started would be around $100 just for supplies but once again you're taking on a pet that you will have for a long time and will cost you A LOT of money.
Please take this seriously, as you do not want your new friend to suffer from giving him away or surrendering him to a shelter, or possibly neglecting him.
You can read more below
http://www.reptilechannel.com/care-sheets/leopard-tortoise.aspx