how much should it cost to fix a stuck lock button?

[Iamgort]

I have a "stuck" lock button on the top of my iphone 4. Warranty is expired. What should I expect to pay for this to be fixed? I have an appointment scheduled but I am wondering if I should start banging the reserve 4s button on the site or not....thank you in advance.

 

[miles01110]

75% of what the Genius tells you.