Please be aware that Taipei and Bangkok has multiple airports and that these results are for all airports serving the city.
The best day to arrive at Taipei is Tuesday and it would be best to avoid Thursday, as prices are on average 82.13% higher than on Tuesday. (Average prices, based on 209 datapoints.)
The cheapest airline flying from Taipei to Bangkok is Thai Lion Air. They are 70% cheaper than Thai Airways. (Average prices, based on 201 datapoints.)
The best time to fly is at around 21. (Average prices, based on 349 datapoints.)