I have a basic bike from Kmart and a bike trailer. ebay sells them for around the same price as the stores but with the ebay ones you can get have them double as a pram..

mine is just a basic one from Kmart or Big W I can't remember which one now.. I love it and have had it just under 3 years. Still going great. I don't use it as often as I did when I first got it though

For DD when she was younger we used to put our spare baby seat in the trailer and anchor it in by tying it up and I just felt better (she was only 6 months old at the time when we got it)