ควรขึ้นบัสเพราะว่าค่าโดยสารจะถูกกว่ารถไฟใต้ดินและรถแท็กซี่.
The bus fare is cheaper because of the subway and taxi.
Should the bus because the fare is cheaper than subway and taxi.
Should take the bus fare is cheaper because the subway and taxis.
The bus fare is cheaper than the subway and taxi.