Untreated sleep apnoea has a HUGE effect on a person's day to day life, and it can cause a number of different health problems. It leave a person feeling so exhausted that what energy they do have goes into getting through the basics. I'm not at all surprised he struggles with motivation when he is so sleep deprived. It's the sort of thing you don't realise how crap it's making you feel until you get the treatment for it. It's like getting a pair of glasses and seeing clearly for the first time. $1000 is not a small amount of money but it would be completely worth it to get the C-PAP mask. It will also make losing weight easier because if he can sleep better he won't crave the sorts of things people who are sleep deprived crave because their bodies are so desperate for energy. It really messes up the hormones involves in hunger and satiety too.