How much difference is there between a x50 zoom and x60 zoom on a digital camera?

You will have an image about 20% larger at x60, but there is catch. Usually magnification of that amount is a combination of the optical zoom and digital zoom. The total obtained by multiplying. With digital zoom, the quality will likely decrease faster as the magnification increases. So normally, the optical zoom will go to maximum before the digital zoom begins to operate.

So if the x50 has 10x optical and then 5x digital, it could produce a better image than 6x optical with 10x digital zoom (unless the optics are not that great). It's good to know which is which. See if you can find reviews on both.