He is the most deserving in my eyes. Money doesn't come into it unless you use it as an emotional appeal to viewers during the time in the house e.g. Jackson and his son, Lateysha and her daughter, or gangster's daughter Chloe (winner) last year.
Jason may have money tied up in his house and business(es) but if he needs money why should he lose his home or livelihood if there's another way? And he didn't expect to win anyway!
He did mumble a couple of things about the money actually. Something about being able to do 'a lot of good' with the 20k, then in his interview he mentioned something about his dad. Both kind of slipped out and I didn't know what he was talking about.
Today I've read elsewhere comments that his dad is sick in hospital and that maybe he can use the money to help him. I don't know anything beyond that, or how true it is, but it seems an odd thing for people unrelated to him to say if it isn't true, and it fits in with his interview. It makes the letter from his dad potentially all the more poignant (which would be another moment he could have absolutely milked like most of the rest of them would have, but as per usual he didn't comment on it).
A wonderful winner, and a perfect ending to what was a farce of a series!