I got my Rosa for 100 Mil during a Xmas event in 2015.
But fair price for her card a few months ago seems to be about 350-400 Mil.
Oh, a lot of these rNPCs will eventually be made recruitable. Right now, we have VV and Cherlyn. In the Orden patch, Spy Olivia and Liung will be recruitable (source
). Liung will be recruitable too by this patch. And in kGE, Rose, Rosa and BFC are already recruitable.
Of course, who knows when the patch will come to our server. So my advise is if you are just collecting, wait for them to be recruitable.
I am trying to find a link for you somewhere. A lot of the LS characters will eventually be made recruitable. They will appear in the order that they were released in LS. Some exceptions will not be recruitable.
Here is the link