For those along the JMT, An easier option is paying Red's Meadow to pick up your package and bring it to their resort practically right on the JMT.
However, I thought they only charged $20 (since they can drive the supplies right up to their store). But their current instruction sheet indicates $40.
Suddenly makes the MTR charge of $80 to handle your resupply bucket seem cheap given all the handling it requires to get your bucket to MTR.