The Galaxy S4 has now been released so I am unsure if you still require a figure. However, just in case you are still wondering. In the UK you are able to get the phone on most contracts for free. Some servers require a deposit others require nothing. The line rentals vary from £25 - £75 per month, it really depends on what you want from your phone and what extras you require.
However if you want to buy the phone outright the prices I have seen advertised is around £500.
- 1.9GHz quad-core processor
- 5-inch 1080p Full HD super AMOLED display
- 13MP camera with dual camera technology
- Slim & light design
- S Health app
- Group Play functionality
- Effortless experience technology