The breast pump wasn't free. It was '100% covered,' unlike most of the other stuff on ARSEN or anyone else's plan. He pays monthly premiums AND most likely a deductible, so the insurance company is getting their money no matter what, same for the device maker, who by the way probably marked the thing up 500% to begin with.
The data suggests that breast milk is better for a developing infant, so this insures ARSEN's baby gets a better start, hopefully requiring less medical treatment as a result, which saves everyone money.
It's not like his wife got a free boob job(which would be awesome, but whatever).