Max security prisoners in NYS are only allowed 2 packages a year. Wages are used to buy food, socks, underwear, toothpaste etc from the commisary. Their prices are not cheap.
That's not true. When I retired in 2003, all prisons ran on the same directive. They were allowed 3 packages a month, and the total of all three packages could not exceed 50 pounds. The only restrictions on packages were for inmates locked in special housing, or inmates who had lost their package privileges due to disciplinary, and that would only be for a very short while.
And they get their underwear from the Clothing Officer...just like they get a set of clothes when they are released. Inmates pay no sales tax on anything they buy from the Commissary, and the prices are cheaper than what you and I pay.