GarageSale 7 fundamentally changes how the application works. There is no more differentiation between templates and running auctions. Everything is a listing right now. There are two main reasons for this:
eBay makes it super hard to launch duplicated listings by now. So having a single template and launching multiple auctions from it without modification doesn’t work anymore. Event if you modify a template to outsmart eBay’s duplicate detection, you loose the ability to easily revise the listing you initially listed.
We are trying expand to other marketplaces with future version of GS 7. The whole “your listing will end after x days, and then you have to restart it” thing is pretty eBay specific and doesn’t apply to other sites.
Once of the consequences of “everything is a listing” change is that you can only launch a listing once. If we were to allow to start it multiple times, we would override you original listing’s item id, listing address, and fees.
Therefore you see this alert, when you try to start a listings that you already launched in the past, that asks you if you want to start a duplicate listing. Since some users find it annoying to move the original listing to the trash manually, we added to this convenient checkbox you were asking about.