This is not easy to answer.
I think that if you can afford it, go for it !

You will/should get the following benefits :

1. Easy quick check-in with at least 30kg allowance
2. Use of the lounge before departure with food and drinks (even spirits)
3. Separate gate entrance for easy boarding
4. Larger seats, less crowded, better meal/drinks
5. Deplane first to be at immigration ahead for quick passprt check
6. Get your luggage first on the carousel

This is if all goes well !

Is it worth it ? You decide

Have a good flight

Also I assumed you meant TG and not TH ?