Someone please help me. My fiance and I don't see eye to eye on this.?!

My fiancé and I are disagreeing. This whole ordeal started when his parents found a condo for me and Joe to look at. So we sat up an appointment with a realtor for Monday night. Well his parents got an appointment to go look at it Monday morning before us. And they liked it, they thought it had great potential. So with that thought in Joe's mind we went Monday night to see it. Long story short it was a dump. It needs new carpet, tub, appliances paint throughout. I saw there was no way potential. Well Joe's dad came up with ballpark figures on his own. They were wrong needless to say. So I called 5 realtors and they all said the same. It's a waste. The crime rate is high in that area and it's like a dump. So anyway I told my fiance that this argument we've been having never would have happened if his parents didn't go look at the place give their opinion and come up with figures on the place. I think it needs to be our responsibility mine and Joe's to find our home on our own and when we do and agree on it then we can bring the parents in and ask for their input. He thinks the opposite that there nothing wrong with his parents shopping for is a home. What should I do I can't get through his head that we two need to do this on our own. We had an agreement that if we couldn't find a place we both agree on together than we'd just rent. Joe set his heart on this place because his dad said there is great potential in the condo. So that proves his dad opinion has an affect on Joe. If we saw this place before Joe's parents then we would have turned around and said no thank you! Help please what can I say to him that he'll understand that this is supposed to be something we must do alone together without mine or his parents.