What do the Irish `travellers` contribute to our society?

From what I have read / heard about them, I would imagine they contribute very little to society. About a month ago I went through Murphy's Villiage, SC which is a small community northeast of Augusta, GA and is a communtiy of Travellers. You would not believe the houses they live in, $500,000 to $750,000 homes EASY! I took some pictures and rode through a subdivision a couple of times, just gave me a wierd feeling. I got the feeling that there were a lot of unseen eyes on me.