The korbanot include cattle, lambs, goats, birds, and meal-offerings of various types. How much would each one cost (in Talmudic money or in today's?), and what was the total cost of the communal korbanot each year paid by the 1/2 shekel tax?
There are some essays (in Hebrew) on the realia of the Beis Hamikdash, including its economics, by Prof. Zohar Amar, on his website (http://zoharamar.org.il/מקדש/).
His study of the korbanos tzibbur (ההיבט הכלכלי של קרבנות הציבור במקדש) suggests that the costs of those, plus various operating expenses (not all of which are known from our sources), would have amounted to at least 4000+ gold dinarim, or 50000+ half-shekels. (To address Al Berko's point in a comment on the OP, Prof. Amar's data seem to be based on the late Second Temple period.)