I love my Samsung galaxy 4 8.0 but recently the screen was shattered in a car accident. It still responds to touch, its just the glass. How much is a typical glass screen replacement?? I've heard it can be as much as the tablet itself. If that's the case I am considering buying a Samsung tablet 4 7.0. Is the only thing that's different between 4 8.0 and 4 7.0 the screen size? I have been using a second hand Samsung tablet 3 7.0 but I find it slower and lagging. I miss how fast my 4 8.0 is, will the 4 7.0 be just as fast?? Thanks!!