I cook pizza at home all the time, bread flour is around 40bht in the local bakery suppliers.
Tomatoes from the wet market, mozzarella from Makro is about the biggest expense.
But a large pizza with several toppings costs around 50bht (depending on toppings) to make.
Had hot dogs for lunch yesterday, Prime English breakfast sausages around 14bht each, so lunch with 2 hot dogs cost around 30bht (OK I cheat and wrap in sliced bread).