Also can a developer edit these scripts and make a new product without too much difficulty? How much time/money do I save by using one?
I suggest you post on a freelance network for quotes on the cost of cloning. I also know you can buy white-label software from various vendors.
I'm an ecommerce and digital marketing professional and also have many years experience in web development.
I recommend going with a WordPress based site, because there are many available themes already, and a huge community of developers that can customize them without much difficulty.
Here's a great list of Groupon clones:
5 good examples of Kickstarter clone themes:
Clones of wish.com seem to be a bit harder to come by. Here's a non-WordPress one called Shopr https://www.appscrip.com/wish-source-code-for-m-commerce-ios-android/ - It's based in Angular which is a fast and well supported new web framework.