Like some of the others say, jealousy is a natural emotion that can be used positively to set goals and help you strive but don't let it dominate your life. Each day I try and think of all the good factors in my life and count my blessings. If you're healthy and your family are healthy that's everything, it really is. Not wishing this upon any of your friends but cancer, illness, an accident or bankruptcy could easily strike and transform their lives overnight.
I do agree with GenerationX, all this moving to get further up the property ladder is not all it's cracked up to be. Take the extreme example of Chris Foster. He killed his family and animals because he was in so much debt and yet to others looking at his life they thought he had it all in terms of material possessions. His assets were worth £3.1 million and yet he'd run up debts of £4.4 million. I don't know anything about your friends' financial situations but for all you know they might have very little equity in their houses and they all could be trying to compete with the others' lifestyles and have a immense credit card debts. What you see of their lives for a few hours might be very different from the stress they're under behind close doors!
Odd as it seems now, moving to a different area might be very propitious for you in the long run as you'll make other friends and acquaintances outside the bubble of your friendship circle that sounds a little bit competitive and exhausting (or am I just reading the context wrong at this time of night?)
Have you ever thought about helping out voluntarily for an hour or two a week in your area? It would help you get to know people in your area and you'll see for yourself that some people who are financially poor are also rich in other ways: talent, generosity, humour, cultural awareness etc and are happy just being ...still and remaining in the house they're in.
Look at the glass half full and all those others cliches about positivity! We don't know how lucky we are today in terms of financial comforts nor when it all might be taken away from us. Some of the happiest and most optimistic people I know have known great hardship and yet they're dearly loved and appreciated by those around them. Isn't that what's most important than racing up the property ladder?
Can I ask you a question, are you friends a bit WAGish? Is it all about emulating the footballer lifestyle? Does the whole conversation revolve around what has been bought and how much their house is worth? Or have am I misinterpreting the situation?