Whats the going rate for getting shatter made?

A buddy in town has a recirulating butane extractor and im thinking about getting him to do some processing. Ive got a 1/2 lb of primo bud that i cant stand the taste of and another 1/2 lb of random fluffy buds and shake. What kinda return should i get out of this in shatter? Also he takes 10% as payment does that sound reasonable?
Ive smoked his shatter before and he does a very good job.