If you can get one with a slide, they sure are nice. It seems like so much more room. You can't go too wrong buying one used. If you decide you can upgrade in a couple of years, you won't take a beating like buying a new one.
When I got married 24 years ago my wife couldn't believe that we camped in trailers. She said that wasn't camping. It only took a couple of trips until she was converted. Now she would never go back.
I think camping is one of the best things you can do as a family. I never forgot the great times I had as a kid, so I wanted to give my kids the same opportunities. Now my kids are almost grown. Soon it will be grandchildren.
Good luck.