It takes 2 blocks of vertical inventory space which really annoys me, a screw driver is usually about the same size as a can opener or torch ( Which both use 1 block). Why not in game? I find that when I have no backpack but really need a screwdriver to open my cans for food that it takes too much space.
For alpha, about 10-20 $ For Beta 25-30 $ Full Release 35-50 $ I really hope it is a cheap alpha, especially if it is really really full of bugs, should be even cheaper.