Thank you! This is the one we had in mind as well, I was just wondering if there any other options, but the DS-2CD2432F-IW really seems to be the best value for money.
I find AliExpress very hit / miss. I would only recommend it for something you are already familiar with (so re-ordering a product you already know at a cheaper price etc.) Buy something from there afresh is a risk because oftentimes, yes the price is less, but ultimately it ends up being...