I want to get engaged. S/O doesn't.

I want to take another step in our relationship. I feel that we have been in the same place for so long and we need a new adventure. My boyfriend and I have been together 7 years almost 8. We have also lived together for 3 years. He doesn't want to get engaged. When ever we talk about it he always says he wants to have a lot more money. Personally, marriage is something that is important to my beliefs. What should I do??