Not legally. There are underground exchanges and black markets, etc. La Leche League can hook you up.
Human milk can be obtained from a milk bank with a doctor's prescription[1] and sells for $3-5 an oz.[2]
[1]http://milkbankne.org/receive/
[2]https://lactationmatters.org/2013/11/08/why-is-donor-milk-so...