If money is all you're thinking about, I really think you should consider whether you want to be a parent.
This child is going to grow up without a father, not because of tragedy or because you used donor sperm to create your desperately-longed-for baby. But because you had a one night stand, unprotected, with a man you'd already decided was not a suitable life partner having previously been in a relationship. Who doesn't want a child. Really, REALLY doesn't want a child. No matter how amazing a mum you had, how do you think it would have affected you growing up to know that your father was so disinterested in you that he wanted to have you aborted?
If you have anything further to do with this 'man', there will be lifelong consequences for your child. If he's paying child support, the child is more likely to know of his existence. If he's paying child support, he might decide he wants contact after all. Or perhaps his parents will decide they want to be grandparents and push for contact? Can you handle 18+ years of co-parenting with a man you can't stand and/or his parents?
It sounds like you want to raise this child. Good on you. I would do everything you can to give your child a fabulous life, one so good that they don't miss having a dad. Remember that your child will come first, always, and relationships with other men will probably have to be non-existent for many many years. Make peace with being single for a long time. Do not even think about introducing a rotation of 'stepdads' into their life.
And while I normally would never advocate lying to a child, if I were in your position I'd seriously consider telling your child that they were a donor baby. At least until they are an adult. I don't know if I would actually do this or not though, to be fair - children do deserve to know where they came from. Even if where they came from was an unwise unprotected one night stand with a 'man' who is utterly irresponsible.
I know this is incredibly blunt of me but please, please think of how your day to day life will pan out over the next 18+ years when considering how to proceed. Flapping over whether or not he should fund a child is not the issue. This is not a property or even a pet. It is a PERSON.