How much does it cost to repair iphone screen, home button, camera and speaker??

Apple does not repair iPhones, but will replace the entire iPhone for a flat fee; see the Service Pricing section here:

http://www.apple.com/support/iphone/service/faq/

There are independent iPhone repair services that may be able to perform a repair for less, though with multiple problems I doubt it. Do a web search for "iPhone repair". Note, though, that if you elect to have the iPhone serviced by an unauthorized shop, all further support from Apple will be voided.

Regards.

Wow, did you run it over with the car???

I'm siding with the idea that given the damage it may be cheaper to replace. Especially if it is an i5, much less serviceable than its predecessors