Bangkok School

Normal sort of dilemma. Looking for a low - mid range priced normal school not international. My kids both attended a school in Phuket which was superb and only 16,000 Baht per term (3 terms per year). It was Thai first but also had English Curriculum and even Chinese Language classes. Here in Bangkok, around Sukhumvit Soi 6 and 8 area where we live, we have so far only found either International schools at silly per month or Thai schools at zero per month. Does anyone know where there could be a normal school for normal income families with kids aged 4 and 6 in and around Sukhumvit Nana - Asok or similar?

Thanks in advance.