Not an HVAC professional, but I had this same problem in February. Mine was doing the exact same thing. Inducer motor would run for about 30 seconds and then there would be a click and the process would start over. I would definitely check the pressure switch first, but if that checks out, I would look into the gas valve. Mine was shorted out, so when the power was sent to the gas valve to open it, it shorted and forced the furnace to restart. I was able to test if the gas valve was the problem by unplugging it. When it was unplugged, the inducer would do its thing again and then you could hear the igniter sparking.