I'm so tired....

ive been with my bf for 4 years and I'm at the point where I'm ready for marriage. His SS and I have the best relationship and he loves me dearly. Although I will never like the way he was conceived (1 night stand) we're still amicable and have a good schedule w his bio mother. 
 

Bf is nearing 30 and I'm in my mid 20s. He thinks the issue lies w financial aspects but I just don't understand that bc nothing much would change. 

basucally I'm tired of him being fully committed to another woman in terms of a child and not to me through marriage... that might be petty but I do everything for him and his son/family. 
how long do I wait or should I?

please help