how long would you wait

My bf and I have been together for a long time. We've had many breakups over the years as we started dating really young. No matter what we faced, we always worked it out and came back together. Lately I've been feeling like I want more. I'm ready to be married and have a home and family. He just wants to move in together. I know that if that happens he will be content so I refuse every time he brings it up. The last time I brought up marriage he told me that he didn't want to get married because he felt like he had to. We're at a crossroad and I know something has to give. Here's my question. How long would you wait before moving on? I feel like if he wanted to marry me then he should. It shouldn't be so hard. He said weddings are expensive. I told him I would rather be broke and happily in love than to be without him. I'm so torn.