Is it cheap of a man to buy an engagement ring for $199 ?

First off, I would like to say that I am not a gold digger at all. I had a very hard life growing up and have worked hard since I was a teenager to support myself. Anyway, I met this guy in 2007, we've been dating since then. In 2009, he proposed and gave me a very tiny ring. The ring was in a box from Macy's so I went on the website and found out the price. The reason I did this was because he has never really taken me out much, but I always notice him wearing very expensive clothing and jewelry. He recently bought a bike for $600 dollars and a gold chain for himself that cost almost $1000. He has been staying at my apartment for the past year, giving me $100 dollars a week to help out. Is this guy cheap and using me?? Should I marry him? Please someone give me good advice. I really need it.