There are no really cheap rooms available. But some hotels in Bangkok or Frankfurt can be of good value with that code. Check dream hotel Bangkok....
Or Citadines 16. It's virtually free at 22 GBP. I haven't stayed at that one, but I have at 11 & 23, & they're all the same - 3.5 stars. In the BKK market they're worth about $60 IMO. There rooms are well designed & roomy. They all have a small pool, gym, & a good restaurant/bar downstairs.