There's a number of similar brands eg MyChild Sienta Duo, Mothercare Hoxton Duo, Cosatto Duet lite etc. The first one was lovely to push, the other two felt heavy. I think Ebay will be your friend to find a cheap one TBH.
Just bear in mind that these are incredibly long when folded - they dont fit in the boot of my car. If you are travelling abroad with a hire car, this may well be an issue.