Please answer my question! Ten Points!?

So my ex bf lies about everything. He will not admit he has a problem. He has sworn up and down that he has no more secrets to hide. So I gave him another chance to come clean about the cost of the promise ring he gave me three years ago. I had asked him where he got the ring, and he said he didn't remember I now know why. That was shortly after he gave it to me. He told me the ring cost $300. Recently he has also told me it actually cost almost $400. I don't care how much it costs, and the actual amount he spent was $150, which was a week of pay for him at the time. I think that is very generous and sweet. I was looking at aquamarine rings the other day online and I saw my ring on the jcpenney website for $150. I am absolutely sure it is my ring. I wouldn't even care because he is my ex but he keeps saying if I work out my issues he wants to get back together. It was a 4.5 year relationship. The thing is he can't even admit he has a lying problem yet. I think it may even be so bad that he told himself he paid that for the ring for 3 years and now he might even believe he did. What would you do? Every time I ask him about a lie he is extremely defensive!