New hard drive before i ever boot up my new Roamio?

Ok so I just purchased a refurbished Roamio with a tivo mini. I jumped on that $300 deal.

Should I just go ahead and drop the coin for a new hard drive right from the start? This way I could transfer all my shows from my old Premiere to the new Roamio and not loose any shows?

Or is this a bad idea to do a swap right away.