You can look for below hotels and choose 2 bed option,
Aira
Ramada wyndham
Grand President
Mercury
Radisson, soi 13
Check in agoda.com, you can see option for 2 adults and kids option on r choose 2 twin bed and 4 people easily can stay stay as rooms of Ramada wyndham, Grand president are big
Check out Ramada by Wyndham Bangkok Sukhumvit 11 on Agoda:
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If not choose 2 rooms and price might be around $50 each for above hotels if you book in advance and choose free cancellation
Usually asian currencies like Indian, Vietnam, cambodia etc has low exchange rates anywhere in the world, it’s not scam when you exchanged from authorized bank, these are their bank’s official rates, always suggested to carry USD