Another thought Debra.. would a charity give a grant for the amount, either a local, one or a bigger one. Although £150 is a lot for you its not a lot in terms of grants. You could either argue its for his neede or your for respite that he goes away. Youd need to put forward a good case but it could be worth a try

Or putting up a case on just giving or similar . I get amazed how much strangers will pay. You'd only need 150 people to do a pound each