How much money is 200 zuz (in today's terms, such as dollars)? Or, how do we contemporanize the value of 200 zuz?
I've thought about three ways:
1) First method: The intrinsic value of silver 200 zuz = 200 dinar = 50 shekel 1 shekel is about 1 ounce of silver 1 ounce of silver is about $10 today. So 200 zuz is about $500
2) Second method: Value of a man 200 zuz = 200 dinar = 50 shekel 1 shekel is about 1 ounce of silver Value of a man (erech) is 20 shekel So 200 zuz is about 2.5 times the value of man I imagine the value of a man would be at least net income for one year, which would be at least tens of thousands of dollars.
3) Third method: From the Haggadah A kid cost 2 zuz. 200 zuz would buy 100 kids Today a kid costs perhaps $30 So 200 zuz is about $3,000
What other ways are there to get an intuitive understanding of the value of 200 zuz in the time of the Talmud?
The standard way is your method number #1. However there were two different weights for Shekalim in the Gemara: Kesef Tzuri, which is the one you used, and Kesef Medinah, in which the measurements were one eighth the size. All d'Oraisa measurements are in Kesef Tzuri, d'Rabanan in Kesef Medinah. Notwithstanding, most Poskim hold that even the Kesuvah of an Almanah (which is d'Rabanan) is also figured in Kesef Tzuri.
As for your second method, the Erech was a set amount set by the Torah which was universal for every person in that age group and was not determined by earning power, nor by any other value of the person.
As for your third method, there were those poskim who suggested such an approach. (It is accepted that the first to propose this is the Sema (Choshen Mishpat 88:2) but the Shach (Yoreh De'ah 294:16) attributes this opinion to Rema.) However, there is no need to wait until Pesach to find out what a Zuz could buy (e.g. four Se'ah of wheat, Kesuvos 64b, or one fourth of day's work, Bava Metzia 82, among others).
The Mishnah at the end of Pe'ah (8:8) tells us that if a person has 200 Zuz in their "bank account," the person is not considered a pauper by Torah definition (with regard to Ma'aser Ani and Matnos Aniyim), since that is enough money to support himself for an entire year. This seems to be the idea behind the Kesuvah as well.
See also Rav Aryeh Carmel at the end of "Aiding Talmud Study," for some more comparative values based on the purchasing power then and now.
Note that the difference between the price of an ounce of silver is about 1/50th the price of an ounce of gold today, while in the times of Chazal and the Ba'alei ha'Tosfos gold was only about 12 or 24 times the price of silver (see Tosfos Bava Metzia 44b DH Echad)