Some things to think about:

Are you sure you want to invest your money into fixing up his house? If you do break up you will not get any of that money back. Also, as long as you are helping him financially he has less of a reason to marry you. He is getting the help anyway.

Are you living with him? If you are his/your expenses will not change if you are married. He is using money as an excuse, not a reason.

He may act badly to a threat of leaving him if he does not marry you so you might not want to make it until you are ready to leave. You could set a deadline for yourself though. Decide that if he has not committed within a set period of time (6 months, 1 year, etc.) you will leave him. That way you know there is an end to your time in limbo.

As long as you are living with him your chances of meeting someone who is serious about being married are slim. If marriage is really your goal, you are spending time with no long term return. On the other hand, he can be as committed to you unmarried as he is married. Many men with rings on their fingers are out running around while the women are home wondering where they are. Being married does not guarantee anything. He could just be afraid of marriage but love you dearly and want to spend his life with you. Only you can decide the reality of the situation and what you are able to accept. I hope you settle things soon and you have a long, happy life with whoever you settle down with.