Hi I'm planning my itinerary to Taiwan .

By bus: you can take bus no. 1860, 5503 or 1623 to Taichung directly in around 130min. The fare is 240NTD per person.

By rail: take THSR shuttle bus to Taoyuan High Speed Rail Station in 25min at a cost of 30NTD per person. Then transfer to a high speed train to Taichung within 40min. It costs 590NTD per person in the standard carriage.

Just choose a suitable way to go.