cobbled streets eh...well being from the uk there are definately a few here. Apart from the cotswolds my suggestion would be to travel north as we have a lot of cobbled streets up here! Personal recommendations would be:
I have suggested all of these places because it is definately cheaper to visit the north of england, however if you want to explore further you could try the Southwest of england for places such as:
Bristol will allow you to get to the cotswolds pretty easy...you could try other towns such as market towns like hereford.
If you need any more info i will be happy to help. I think you should try and get into Wales as well as its very beautiful there.