be mindful of what is advertised as TSS out there.. most of the "cheaper" stuff is a blend not pure tungsten and cc/kg is not the 18 of pure TSS... you can do this yourself and purchase blends that are much more affordable for waterfowl (sky blasting). another thought is that if you buy bulk TSS it may be cheaper but a large investment ( if you had a waterfowl club) ...
i think ballisticproducts has data and blend for sale... i think i have found strait TSS for 41$ ish a pound best case...in 5# containers... enough to load say 17 7/8 rounds per pound...

your 2.40$ each number....
not really cost effective for ducks/geese (IMO) to run strait TSS, even sphero (15cc/kg) is mid 30$ / lb.... not much better pricepoint… deadly yes but
oh, take a look at apex ammo, they may have box ammo you would like and if military, you get a discount too