I have been saying in ALL my posts here on Optune since 2014 [18 hrs The only thing that has changed is the weight from 6 lbs to 2 lbs. NVCR is working on reducing that time of 18 hrs via transducer technology improvements.
Could you ask your Optune friend how long has he been on it? Also how much of the $20,000 is OUT of Pocket?