The cheap ones are 12-14$ us, they will be very delayed but work for idle speed or to see rpm when cruising, also hour meter seems to work, has counted 60.1 since may...also very difficult to see unsless cruising on steadier ground, the lettering is pretty small,hasnt been affected by water but sitting in the sunlight will make the screen get all funky for a while.......i will probably try the next step better next time i get one