It could never be totally certain, but it would be a pretty odd coincidence if exactly that amount was saved by chance, including the markup! That's if it really was 8%, of course. Accorcing to the Mishnah, an agio of 4-8%
had to be paid if the
money had to be changed, or if a half-shekel was paid for one person; there was no agio if a full
shekel was paid for two people. Trouble is, the Mishnah is essentially post-bar Kochba, so we're talking about evidence from a century or so, very roughly, after the destruction of the Temple and the end of the tax.
However, a second
hoard was found on Mount Carmel in 1960, consisting of 3 400
Tyrian shekels, 1000 half-shekels, and 160
denarii of
Augustus. It was buried after 53 AD, the date of the latest
shekel. Leo
Kadman (
Israel Numismatic Bulletin No. 1, 1962, available online at
http://www.begedivri.com/shekel/teachings/kadman.htm) argues that this represents the
Temple tax for 7 800 Jews, and that the
denarii represent the agio of 8% on the half shekels exactly. According to the Mishnah, the Temple rejected the debased
denarii of
Nero,explaing why only those of
Augustus were used. As we have not one
hoard, but two, showing the same characteristic, on top of the somewhat dodgy written evidence, I think it's as certain as it can be considering the dates we're talking about.
Hendin's argument would have been much stronger if he'd cited the evidence properly.
