Vietnam Airlines from Frankfurt to Bangkok has 2 flights every day. And there are 10 flights per week flying out of Frankfurt which connect to Bangkok.
The price for economy class – one way ticket of Vietnam Airlines from Frankfurt to Bangkok is 14.074.000 VND (or ~$702 USD) and the price for bussiness class – one way ticket of Vietnam Airline is 36.889.000 VND (or ~$1842 USD).