A Virtual Copy is called "virtual" because it is not a real copy. Whatever editing you do to an image exists only as a couple dozen lines of code in the database, just editing instructions, and is actually applied only at the time of export. The VC is a second, alternate, version of of the editing instructions, another couple dozen lines of code in the database. (About 25 KB worth, as a matter of fact, about one thousandth the size of a single Raw file.) You can make 20 VCs without using very much space. But putting an image into a collection, either a master copy or a VC, isn't even that big. It is just a single line added to the code that says, "This image also belongs to Collection X". There is no second "destination folder".
BTW, it doesn't make any sense to make a VC unless it is different from the master in some way. Unless the VC is an alternate version you might as well just put the master copy in the collection. For instance, I might have a collection called Best Portraits of Jane in which I put the ten best shots out of hundreds that I have done of Jane over the past year. But I also want to have black and white, 8x10versions of those shots ready for immediate access, so I make VCs, convert them to b/w and crop them and make another collection Best B/W Portraits of Jane.