If you want an own root rose, I don't see why not. Personally, I have never bought an own root rose but I have often seen my roses which I plant with the graft at least 5cm below ground start sending out roots above the graft. Interestingly enough I have just potted up a side cane of Deborah (aka Play Rose) that had rooted.
However, and somebody please correct me if I am wrong, some roses just don't perform on their own roots. I would think though, that a rose the roots easily will probably grow very well as an own root.
